Thank you for making this enjoyable video. Bought a used 2004 2500HD CC long bed LT with the 8.1L in 2005 with 19,500 miles. Was like new and paid $22,500 for it. The truck just turned 300k miles and has proven to be one of the top purchases I’ve made. Repairs: 1 coil pack, 4 sets of plugs, TPS replacement, 1 alternator, 1 master cylinder, all new brake lines, driveshaft carrier bearing, Windshield washer pump, new AC compressor and I’ve had various electrical issues (none severe). Normal brake maintenance etc.. Have friends that have purchased 4 or more trucks in the time I’ve owned the 2500HD 8.1L and have not once felt the need to shop for anything else. I believe, in several ways, buying a new truck would be a downgrade.
glad you enjoyed. I agree with you, everytime I look at one of the new trucks, I end up taking one of my 8.1's on a day trip and remember why I have no interest in upgrading...
Love these engines. My 2002 burban 2500. Pulls like a champ starts every time. 10500lbs camper hooked up. Never misses a beat. 4l80e holds the power just just fine nice crisp shifts. 201000 and climbing. It’s a shame when something this reliable comes to an end.
Yep, definitely a powerhouse for the ages. Good thing I'm a believer in second chances😁. I should have it finished up and back on the road in the next couple of months.
My 2004 Suburban tows a 12 ft cargo trailer all over the USA. 15 mpg on a good day. 250,000 miles, zero problems. If it had more gears it would get even better mileage.
I bought a 2001 2500HD new from the dealer with the 8.1. It is still my daily driver and my work horse @ 326.000 miles. I had to put a cam sensor in at 100,000 miles but no other issues. The truck itself has been beat to hell and back but keeps going. I have a couple of small leaks from oil lines and it burns a TINY bit of oil since day 1. I expect to have this truck and engine for at least another 250,000 miles. Yes, it has the Allison and I love that thing too.
Yep, that seems to be the overall consensus from long term owners of the 8.1 equipped trucks. Long term reliability in a truck, especially if you're on the road or using it for business makes your life so much easier. Thanks for the testimonial👍. I'm looking forward to using my 8.1 as a daily.
Now that's a testimonial! As much as some might complain about fuel mileage, these engines make up for in how long they will survive and keep working for you.
A neighbor of mine just put one in an ASTRO van...! It was already LS swapped and not surprisingly because it's a GM product, it sold right in place of the LS with very minimal changes...! It's probably the fastest ASTRO van in Florida... Thanks for sharing... Keep up your awesomeness...!
I just bought my 1st 8.1 in a 2500 HD GMC Sierra and I fell in love on the test drive. Amazing how quiet it is and how smooth she rides. I’m the 3rd owner. Last guy had it for 3 years and an old man had it from the showroom floor before that and well cared for the whole truck.
@ 8:20 - 8:25 = (Lost Foam Casting ). I have this Vortec 8.1L in my 2000 National Surf Side . It's perfect for my application . It's the next best thing to a Diesel pusher . Thanks for the Great post .
@@VetteSourceit would disappoint you. 😂. They only build them to about 375hp/450lb and the boat is 17,000lb. Boat cruises at 26mph @ 3400rpm and prob about 40mph at WOT. But the boat is sleek looking and looks like it would cruise at 50mph 😂 oh ya, and gets 1 mile per gallon at best. 😮
i can speak personally for this engine. i had one in a 2009 GMC c7500 and hauled GCWR of over 30k daily. had the 6speed manual trans and was geared very low. this engine spent most of its life at redline. i drove this truck with 75k on the clock for 3 years including a trip from St. Louis mo. to Fresno California. that's 4 days driving almost 12hr days and it topped out at 65 so it was pegged the entire time. the truck/engine never complained. stayed cool and kept running until we retired it at 80k and i was given a 2021 f750 with the 6.7, wish i still had that old gmc lol.
Thanks for the testimonial, Richard. It's one I've heard often about the 8.1's, and the regret once the owner/operators don't have them anymore. When you're using your truck for commercial purposes over the road, reliability is king, and the 8.1 has that in spades.
I really think you missed your calling with this vid. Great explanation and detail, it's like a show aired on the history channel for the 8100!! I rarely turn that bell icon on for any channel but I will for this one!
Two comments about problems I’ve experienced with this engine… 1st glad you showed the back of the block. At about 90K miles I had the crank sensor fail and leave me in a Walmart parking lot. It’s not serviceable from under the hood, you have to reach up from underneath, around the bell housing and try to pull it out. In my 40+ years as a shade tree mechanic, I have never come this close to curling up and crying uncontrollably. I ended up having the truck towed to a local dealership for repair. At this point there were just wires coming out of the hole. When I asked the mechanic how he did it, he said “plenty of thread penetrating oil and a curved set of needle nose pliers”. A very frustrating and expensive learning experience. Second on the list, on my truck the exhaust pipe crosses behind the oil pan by just a few inches. Not a problem unless someone tries to use an impact wrench to remove/install the oil drain plug. The hole has been stripped for a number of years now and I can’t get any of the typical oil change businesses to change my oil because they don’t want to deal with a vehicle with a temporary plug in the pan. It’s a bit of an irritation at times. Other than these items, the engine is still running strong after 20+ years. Not too shabby
Hey Rusty, those are good points. Thanks for sharing👍. You're absolutely correct about the crankshaft position sensor. I had to remove it from the 3500 truck after I first reassembled it, and it was not a fun job, even with the extra space created with the factory 2" body lift. The aluminum oil pan is an interesting feature as well. It actually feels pretty solid, but I never thought about the oil drain plug stripping the threads. You may have already investigated it, but the new oils pans can be had for around $125 through rockauto or Amazon. Not too hard to change either once you drop the lower crossmember.
In our Motorhome I had the crank sensor fail intermittently. Went to pull it ( easily to get at in this application )and it came out partly. We’ll with nothing to loose I have it a bit more ompf popped out. Lots of never seize on the new one. 2001 workhorse w-22 chassis.
I went through that too and it's a bitch on a big block. My knuckles were torn up by the time I was done.But ever since it has been very reliable ( besides the rear crank seal)
Great video and yes very few people know about the 8100 Vortec. In my opinion and experience with these 8100's, they are the best ever made. I own a few 8100's and 7400's (all GMC duallies, Suburbans & Yukon XL) and my daily driver is a 2002 GMC Extended Cab dually 8.1/Allison with 4x4 on the floor and I'm close to 800k miles. The motor, transmission and axles have never been rebuilt or replaced. The only major part replaced has been the transfercase about 3 times but other than that, just regular maintance and minor parts it is needing that I have done myself. She is my baby and I take really good care of her always. Many people don't believe me about the mileage (especially diesel guys) and this truck is used to work hard and doesn't give up at all. I have always pulled with it all over Texas(my home) and a few more states and have done alot of traveling in it since the first day I bought her(15 years ago with 32k miles from the first owner like brand new😍) and she still pulls hard like a mean beast. I'm still searching for more to buy no matter the distance.lol Well I can go on and on but I really enjoyed your video and all the info is great and I'm looking forward to more videos and yes, I am a GM Big Block guy too👍Thats all I own since I drive🤠
Galdino, thanks for sharing. Glad to see see other 7400 and 8100 enthusiasts like myself. I too have a mixture of both trucks, with a 2000 SRW 3500 with 7400 Vortec that I've used as a daily driver for almost 20 years. These are well built machines, and like you mentioned will last forever if properly maintained. Im.in Texas as well, maybe I'll see you on the road one day👍.
@@VetteSource yes Sir hopefully one day we meet. San Antonio is my home but I like to take road trips all over Texas to find more treasures. Im looking forward to see more of your Yukon XL. Well stay safe and keep having fun👍
I have an 2002 chevy crew cab dually 3500 with this motor. Bought it 2 yrs old. I still have it. Runs very well...no issues. It does consume some oil but nothing excessive or ridiculous. Plenty of power. I've pulled some heavy trailers and it's done well. It does use gas. 10 miles per gallon in city driving is the norm. Very dependable. Always starts and idles beautifully. Very quite and smooth.
Yep, I have the exact same truck I picked up last year to put back together. It sat in a shed with the engine and transmission laying beside it, with everything piled in the bed for several years. I did some mild prep work, put it all back together, and it runs exactly the way you describe. You have to really try to kill these things.
I've had my 02 ccsb Chevy HD with the 8.1 for 4 years now. I still absolutely love it. It has a custom tune, set up for 89 octane and gets 11 mpg all around average. With 4:11 gears and 285 tires I can manage almost 12 mpg empty on the freeway under 75mph. I pull several trailers but it's biggest impact is my 20' steel frame cargo trailer. It's a foot overheight and bucks wind like crazy. The truck pulls it easy but I average 7 mpg with that no matter how much weight is in the trailer. As far as oil consumption. I've found old school conventional 10-30 is best. I use maybe a quart between oil change. I ran a synthetic and a blend a couple times to try but experienced poor results using as much as 3 quarts between changes to keep the ol girl full and happy. Thanks for your video.
Awesome overview, great detail! I've got an 8.1 extended cab dually, and it pulls awesome. My only complaint is with the Torque Management system, which I intend to tune off shortly. The combo of this capable, simple engine in front of an Allison transmission makes it impossible to justify the cost of a new truck.
Hey Jeffrey, thanks for the comments. These are incredible trucks like you said, but the torque management system is a puzzling system. I am troubleshooting it on the 02 CC dually I rebuilt and it's driving me crazy. Who did you have perform the torque management delete on your truck?
i have an 01 2500hd and it has 180k miles i couldnt ever justify spening 90k on a new pickup as for 10k i can totally rebuild the engine and tranny which doesnt need it. love this truck
I have this engine with the 5 speed Allison transmission in my 2004 Fleetwood class A motor home. It's a 32 footer and weighs in at around 21000 pounds. Fully loaded with everything including the kitchen sink and pulling a Toyota camery it gets almost 8 MPG and never misses a lick. Strong and dependable, and in my opinion the best non diesel engine ever put in a class A. The Ford Triton V10 is more popular in the older rv's like mine but you have to push them above 4500 rpm to make the power the 8.1 makes at 3200 rpm. I also like the idea of an all cast iron assembly instead of the aluminum heads on a cast iron block like the Ford. If you are thinking of buying an older class A and have a budget of around 25k the Vortec Workhorse chassis is the way to go.
Think I was just under 300 gallons for 28xx miles. Still, not a cheap trip. 11.2 - 11.8 @ 80 mph. 7000 truck with driver, 4.10 rear 75 series tire. So, stock basically. Lol
@@VetteSource 80 east coming back. From salt lake city, all the way through to nebraska in the morning, i was driving through blowing snowstorm. O2 3/4 ton avalanche, worn out city tires on the rear, was playing the odds to get back home to my tire guy. Anyway, couldn't see the road most times, occasionally could draft a rig, or get in his eske for a few miles. Auto 4wd, let the computer do the work, concentrated on steering and speed. Every highway gate I came up to in wyoming, I expected to be closed. Nope. Drove on. Ended up being about 600 miles of puckered seat cover. Truck never wiggled, wobbled, or missed a beat. As my friend put it... you could have had slicks on the front, and she would have still tracked right. Mass. ❤ I've got 2 of these trucks. One, is a spare. Bought them both, because saw where truck prices are headed, as the dollar declines. It's the body style everyone skips, I'll take them all.❤ had 1440 lbs of tile tearout in the bed, the other day... wheeling it through rush hour traffic, like it wasn't even phased. Can't do that, with the new half tons, without ending up with an 6spd neutral trans. 🤣
That's the kind of testimonial that keeps people interested in these bad boys. Did you happen to catch the video of the Chevy truck that got caught in the tornado and flipped over multiple times? As soon as it landed upright, the guy just drove off in it. Now that's tough😁.
I just purchased an '01 Sierra 2500hd sle with 217,000 for what I thought was a very reasonable price not knowing a whole lot about the 8.1 except that it is a big block gm. Have to replace a few things on it like lf brake hose and the entire rear bumper assembly because it spent most of it's life in OR then the last 60,000 in MN. A bit rusty. Found it in FL and boy does she purr. After hearing your testimonial and history overview, I'm MUCH happier with my decision! I love muscle and this truck has plenty to spare in stock form. An ox in pony clothing! Thanks for sharing your insight! Much appreciated.
Hey W, glad you enjoyed it. Now that I've been fortunate enough to acquire some of these 8.1's for myself, I'm sure they'll be with me for the rest of my days. Awesome powertrains for sure👍.
+1 for the 8.1, I daily one of these in an 01 suburban. Lots of fun confusing and astonishing people when I tell them just how huge the engine is. To touch on the oil consumption issues as far as I've experienced/read, these engines will consume more oil when run on the factory recommended 5w30. I've found my engine using noticeably less oil after switching to 10w30 for the summer months and I'm currently testing 5w40 for the coming winter.
That's good information. I'll have to try that out once I start daily driving these. It is funny to see the confused look on people's face when you mention how large the engine is. It was one of those options that many never noticed.
@@jimmymcclelland3727 around 8-10 in stop and go traffic, I'm sure with a couple mods, a tune and careful driving that number could be brought up a bit.
I bought a brand new 02 GMC Sierra 3500 Dually with a 8.1gas + Allison. From day 1 that motor would consume 1 qt of oil for every 1500 miles or so. It now has 175K on the odo. About 2 weeks ago I installed a CA legal K&N FIPK before heading out from Los Angeles to Denver CO. I can feel the benefits from the K&N kit in the seat of my pants and interestingly enough the motor didnt use 1 drop of oil on the 2200 mile trip. My guess is the factory intake and PCV system generates a lot of vacuum and the open filter element of the K&N created a drop in vacuum in the crank case. I have always ran Castrol 20/50 oil. Also the fuel MPG has always been 9.5 to 10 MPG. I got 11.5 with a 1984 Goldwing in the bed and doing aprox 85 to 95 MPH on uphill grades.
Great video, the 8.1 builds have jumped the last few years. Hope the pushes for a better aftermarket. The Chevy 2500 Avalanche the 8.1 was the only option. My first was a 1500 started towing bigger trailers and purchased the 2500 installed 456 gears. Love 8.1.
@@user-wj9wq7mk4h I run the stock tire and rim. I like running 16's for the sidewall and less mass.. Craze is at about 1500 miles my MPG jumped. It likes 2200 rpm for best all round MPG. Went from no matter what it was 10 now is 12.5 to 13. I've never seen anything above 14 cruising now I've seen almost 16.
Bought my 2002 2500hd Silverado brand new. Now has 201,000 miles. Contiplating if I should do the timing chain. Right now truck is down for a whole new suspension. Almost done. Did a solid axle swap using 1979 Ford Dana 60 kingpin. 10 inch lift with 40's. As far as problems I have had: Crankshaft sensor went at around 38,000 miles. Common problem with these. Air intake manifold leak throwing p0101 code. I actually drove on it like this for 8yrs. CEL would only come on during hard acceleration. I had a exhaust manifold bolt break off in the head due to heater core hose dripping on it. Was able to repair it with a heli coil. Still holding up after 7yrs. Oil pan gasket developed a leak. Replaced. But after doing the solid axle swap, if it leaks again it will be a breeze to do now. Camshaft sensor went out. Engine would crank and crank until it started. Not too bad to fix this.
I bought a 2003 gmc c6500 truck with an 8.1 Ltr with 124000 miles on it running on liquid injected propane. Now has 330000 miles on it. Just took a compression check to see if it was worth putting new injectors in it. 4 cylinders have right around 150 psi 1 cylinder at 148 psi and 1 cylinder at 161 psi. This is my work truck. It runs 6 days a week mostly city driving. Short runs all day long and once in awhile maybe a 50 to 100 mile run once a month sometimes well loaded. Unreal pulling power. Well worth putting new injectors in it. I am sure the rest of the truck will fall apart around that motor before it gives up. Only thing bad about it is if you think gas is poor fuel mileage, propane is half what gas is. But propane is cheap. the gross vehicle weight rating for the truck is 25900 and it is at its max often. Never has a problem pulling the weight.on the mountain roads of Oregon. I will run that motor until it dies but at the rate it going I think I will be First.
Hey Mark, thanks for the testimonial. Real world examples like yours are what keeps these engine in demand now and will continue to do so in the future. Glad to gear the truck has been such a valuable asset for you.
I’ve been using the Nug Block Chevrolet since early 80’s, if you take of it , it WILL take care of you. I never had one of these, it’s gotta be a Tough Nut. 👍
I have been a fan of the big block chevy since i was a kid in the late 70's. my uncle had a Chevelle SS 396 L78 4-speed car and a flat bottom ski boat with a 454 LS6 crate engine in it. both were super fast. once i was able to drive i got a camaro with a 350 small block but my dad would never let me swap it out. after i got our of the air force i found a 71 Camaro ss 396. not the most potent 396 ever made, but once rebuilt it added a roller cam and got rid of all the smog just, that thing was unreal. consistent 11.7's in the quarter mile on radials. there is probably another .5 - .7 seconds in it if i were running drag radials or slicks. was always festinated with the 8.1L vortec big block. it had a lot of high performance potential with right cam and better after market support.
Hey Shad. Cool story, thanks for sharing. You and I are from the same generation of late 70s/early 80s. My fondest memories are of the BBCs prowling the streets like T-Rexs on the hunt. Even though some of the power output of the newer generation small blocks is impressive, they will never match the sound and cool factor of a BBC with a solid lifter cam at WOT. The 8.1 was an awesome send-off for the BBC, and I'm glad to have finally been able to acquire one to use on a daily basis. Of course, that's as long as I can keep the fuel cost from bankrupting me🤣.
@@VetteSource I know all about fuel cost... my 71 SS 396 get 10mpg. up hill, down hill, pulling a trailer, 70mph tail wind, doesn't matter... its getting 10mpg. but it will crush most modern cars, and even shocked a few Hell Cats that did not realize how fast a BBC Camaro can be.
I have a 2004 ‘Burb with this engine and I’ll never sell it. Pulls everything I have (up to an 8500# camper) and it gets the same mileage if I’m pulling or not. Beast.
Yea, I see engines I want at these yards quite frequently but never have enough time to go back over and grab them. Glad to see somebody is getting good use of them👍.
@@VetteSource I've never seen that many good engines on the same day. My cousin and I pulled all three the same day. We took the radiator support bolts out. Cut the pretty rusty fenders right down the middle. Folded the clip up like a hood. Cut all hoses and wiring. Cut the frame each side. I reached back and got the bell housing bolts, motor mount bolts and cut the exhaust.
@@VetteSource yes sir! It now has a quadrasteer bed and spacers to fill the wheel wells. I have a full out turbo truck and I don’t care about it as much as the 8.1 truck haha. 😅
For sure, the turbo power is cool but there's nothing quite like the feel or sound of a BBC at WOT. Sounds like a couple of great trucks you're running👍
@@VetteSource yes sir, thank you sir. I the 30k I put into the rcsb turbo truck, is awesome, it’s great. However…. Push come to shove, the the turbo truck is gone waaay before the 8.1 rcsb. I will never be the fastest, I just want to build a truck that GM should have in 2002. The real SS. Thank you for your response
Love my 04 GMC 2500HD 4x4 Ext Cab. 316,000 miles and counting. Transfer case has been the only issue. Replaced at 280,000 miles. Pulls as well as any Diesel I've ever driven with far less issues. I have beefed up the brakes and Suspension 4" life and pull 22,000# on the bumper. It has never been babied. It's kinda retired now, only gets about 5,000 miles a year on it pulling 2 of my heavy Antique JD (60 & 80) tractors to show & Tractor Pulls. If your ever in the Boise, ID area, chat me up.
I currently tow a 5th wheel camper with an '04 Sierra with the 6.0. That engine does fairly well pulling 11K lbs. but grunts in the hills. I am now looking for something with more low-end torque and since I am not a diesel guy, I favor the 8100. The Alison trans is a bonus! But, trying to find one with a decent body and less than 200K is somewhat difficult. I love those Vortec engines!
Hey Brian, great name👍. For sure, the 6.0 is a great hauler and will get the job done for most applications. It's when you feel the extra "oomph" from the 8.1/Allison that you realize what you've been missing😁. I agree with you, the Vortec family of engines, especially the big blocks are some of my favorite engines for pulling and reliability. I've been using my 454 Vortec as a daily for over 20 years.
@@VetteSource I am going to look at (buy) a very nice truck with the 8.1 tomorrow. Pretty happy that soon I can put the old reliable 6.0 to rest. When I weighed my truck and camper, the CGVW was 440 lbs over the max capacity of my 6.0. And that's without my generator.
I was lucky enough by chance to find for sale a 2001 Chevy CC dually 8.1L/Allison 4x4 with only 32,000 miles on it four years ago. Had it shipped to New England site unseen. It was titled to a courthouse in Florida and had a steel flatbed on it. Found a clean takeoff oem dually bed out of Texas and grabbed it. Still needs a paint job after years in the sun in Florida but a great running truck. Gas mileage not much less than my 2008 1500 5.3L. Kicked New England winters ass plowing the last few years. As far as the oil consumpsion goes, install a catch can system while blocking off the plenum under the intake manifold and problem solved. Spent years (5+) reading about and watching all I could about the 8.1 before finding this truck. Future classic! Edit: have a 2nd 2001 8.1L/Allison 4x4 164k truck for parts. Also grabbed by chance, can't go wrong there!
Hey Larry, thanks for sharing your 8.1 truck story👍. It sounds similar to my experience with these great trucks. I always wanted one, and finally acquired a 2002 CCLB dually that had been disassembled, than found an 8.1L 2004 Yukon 2500 XL with a blown engine. Then I stumbled across a 2001 GMC 2500 extended cab needing an engine. I'm close to having the first two trucks back on the road, then will start in on the 2500 shortly.
Just bought an 8.1 out of an 03 Avalanche to swap out my 6.0 from my 02 2500hd 4l80 4.10s , from everything I've researched should be a pretty easy swap . There is a book , Chevy 8.1 Vortec 496 performance manual on Amazon $25 , if you have an 8.1 buy this book , tons of good info .
At 235k on my 02' Silverado ext cab long bed 8.1 w/ Allison 5spd. Love the effortless torque and simplicity of the engine. I've had cam sensor, maf dtcs and burns a little oil but besides that solid engine.
Thanks for the testimonial. The general consensus is that the GEN VI and VII BBC's are pretty much bulletproof unless you just outright abuse them. Even then most of the time they'll survive👍
There is an intake manifold upgrade most anyone can do for some free horsepower. You have to pull the intake off and cut the bottom off the intake manifold. There is a plate casted into the manifold inside that you can cut out and it will make right after the throttle body all the way to the back of the intake 50 % larger. You then need to weld the outer plate you cut off to gain access back on. The factory intake manifold stops flowing air at around 4000 RPM, This modification will allow much more flow and a smog inspection station will never know you did it.
I had two of these motors in 37 ft searay for 10 years. Never a problem with heavy use. Compression was the same as when I bought the boat after 10 years.
These things are great. A gen 6 cam slips right in and all you'll gotta do is change it to a gen 6 firing order in the ECU. Monster engine with monster power potential.
My auto tech class had one of these, It was a seized motor that my class took apart and actually learned on, however the other classes spilled the fluids and put a bunch of components inside of the engine along with food and pencils
That sounds about right with an auto shop class. I remember in HS shop class, we received a brand spanking new 1989 Chevrolet Caprice Brougham. Still had the window sticker in it and 3 miles showing on the odometer. Rather than be allowed to learn something from it, the teacher wouldn't even let us tear it down or reassemble it. Instead, it sat around as a static display with the teenagers hanging out in it during class. I don't know which one is worse, but it sure seemed like a waste of a good learning tool.
Thanks for the information, very informative video. I just bought a 2002 3500 crew cab with the 8100. And yes the gas mileage is less than desirable and yes it does have an oil consumption issue. I have an issue on the # 8 cylinder fouling the plug. I’m hoping it’s a valve guide seal as it smokes badly on start up sometimes. It also has a periodic loud squeal after stopping at a red light and then goes away. I believe it’s a vacuum leak somewhere and it could be contributing to the spark plug foul. I bought the truck to pull my 24 ft inclosed Racecar trailer with a 3000 lb race car and tools air compressor generator etc. it does a good job. I’ll tear into it soon and figure out the oil foil and squeal.
Thanks for the feedback, glad you enjoyed it. I have the same truck as yours, and enjoy using it for my over the truck as long as i can justify the fuel expense with the current prices🤪. Even with the few minor issues you're describing the great thing about the 8.1 is that it uses all the next generation LS fasteners and gaskets which makes it incredibly easy to tear into for inspection and repair.
I still run my '03 Silverado 2500HD to this day after all these years pulling our large 5th wheel trailers. Current 5th wheel is close to 14k lbs. Fuel mileage is nothing to brag about but this is a very large engine with little design given to saving fuel. In town fuel mileage is going to be little over 8mpg on average and close to that towing in all conditions. Unloaded on the highway could average ~13mpg if given enough flat roadway. But it really pulls well and that's why we still use it, well that and new trucks are not given away. I'd say we've got our money's worth.
Got a 2005 ,GMC 2500 8.1 VORTEC ,ALLISON TRANSMISSION ,CREW CAB, LONG BED 4 WHEEL DRIVE ( ABSOLUTLEY LOVE IT ) HAD IT ABOUT 3 YEARS NOW , IT'S STOCK ,BUT A BRUTE , IF I WANT SOMETHING MOVED OR TOWED IT'S READY & CAPABLE ,BEST TRUCK FOR TRUCK STUFF I HAVE EVER OWNED JUST TURNED 144,000 MILES ( GET R DONE ) MY BUDDIES SAY TOU'LL BE DAM LUCKY IF YOU CAN MOVE THAT , GUESS I AM LUCKY ! I HAUL CARS ,SCRAP STEEL ,LUMBER , YOU NAME IT , SIT BACK LISTRN TO THE AWSOME BOSE STEREO , SET CRUISE ,& TOW HAUL ,& JUST DRIVE !! SOULDN'T TAKE 2 OF THESE NICE NEW SHINEY PLASTIC TRUCKS FOR IT , THIS TRUCK IS THE REAL DEAL ! WAS LUCKY MAN THAT OWNED A CABINET SHOP OWNED IT , FOR HIM & HIS WORKERS TO GET TO JOB'S ,HE OWNED ,HE DROVE ,HE MAINTAINED TRUCK ,HAD A 18 FOOT LONG ENCLOSED TRAILER FOR CABINETS ,ETC , INTERIOR & ALL GREAT A/C COLD ,EVERYTHING WORKS FLAWLESS , REALLY IMPTESED , LOVE THE ALLISON TRANSMISSION & WHEN IN TOW HAUL IT HELPS HOLD BACK WHEN SLOWING DOWN , ONLY FUTUTE PKAN , I WANT TO PUT DUAL EXAUST ON IT ! OTHERWISE LET IT EAT !! I PASS THESE NEWER TRUCKS ALL THE TIME STRUGGLING EITH A CAMPER ,OR TRAILER LOADED ,FRONT END LOOKS LIKE YOUR ON ONE OF THOSE HUMPD HUMPS AT A DRIVE IN MOVIE .( LOL ) WHEN IT SNOWS I FILL UP A LARGE COFFEE MUG & THERMOS & HEAD OUT REALLY JUST TO RIDE , BUT I DO USUALLY TAKE MY GEAR & MAKE SOME GAS MONEY PULLING PEOPLE OUT , I REMEMBER ONE GUY OFF ROAD ABOUT 30 FEET WHERE HE HAD DUG & SPUN & SLIDE DOWN ,HOOKED EVERYTHING UP READY TO PULL , HE SAID YOU GOT IT IN 4 WHEEL DRIVE DON'T YOU ? SAID NOPE HASN'T BEEN IN 4 WHEEL ALL MORNING & I BEEN THE ONLY SET OF TRACKS ON MOST ROADS , I SAID I WILL WAIT & SEE IF I NEED IT A LITTLE WHEEL SLIP AT FIRST , THEN WITH SOME FEATHERINGBOF GAS FOR OPTIMAL TRACTION ,UP & OUT CAME HIS DODGE HEMI RAM ,IT WAS IN 4 WHEEL DRIVE , HE WAS AMAZED, UNHOOKED DROVE OF STILL IN 2 WHEEL DRIVE ,OH DID I MENTION 8INCHES OF SNOW ON GROUND ,LIGHT SMALL FLAKE SNOW FALLING ,HAD SNOWED ALL NIGHT ! LOVE ME A WORK TRUCK ,& GOT ONE !!
Hey Gary, now that's a testimonial! 20 plus year old truck that makes you money while your out just cruising around. I'll have to save your story for everyone to see👍.
One more thing. I did this swap even though people said it wouldn't work. The 11.5 aam diff was very bad so I replaced it with a 14 bolt corporate. Paid 100 bucks for it.. lol. Same 4.10 gears to match the front. Which to me is one of the best diffs on the market. 40 years with only a few modifications...The only difference is you need a longer driveshaft. Everything else swaps. The only downside is you loose 1 grand towing capacity. Since the corporate is about 200lb lighter than the aam.
1. Oil consumption: mine was using oil and my mechanic pulled the intake bolts one at a time cleaned the bolt and the bolt hole then put sealant on the bolts and it stopped the oil consumption and fouling my plugs. 2. They are known to have problems in the 2001-2003 models with the crankshaft position sensor which can cause the engine to stall while moving but usually will start right back up, run ruff intermittently.
I got a very nice 2001 Silverado 2500 hd with this monster engine, it IS a Duramax Killer! I truly love my truck and in my opinion the 8.1 is the best truck engine ever built by GM !
I would agree. Over the last few years people have figured out just how powerful and reliable this engine actually is, which has kept the value of the trucks and engines pretty high.
The issue with calling it a Dmax killer is the dmax can make 650hp and 1000ft/lbs AND get 20+ MPG. I do love these engines tho and will be building one for a race truck soon
Yea, I think it comes down to a matter of preference overall. I've seen the power of the Duramax, but for a more casual over the road puller, it has always made more sense for me to utilize the gas big block haulers.
Lots of industrial backup generators use this engine turbocharged and made to run on natural gas, or propane. We have one at my job. It's a big Ingersoll Rand
Purchased 02 2500hd w/ the 8.1 n the Allison trans. as a leftover in 03. Only have 145k miles.. first yr dealer replaced the booster.. otherwise with regular maintenance n an Xtra qt of 5 30 oil between oil changes, I'm xtremely happy with it. Using g it as a cement work truck , it was regularly pull heavy trailers with front loader on it with NOOO PROBLEMS. Always impressed as the Allison shifted going up n down hills with heavy loads. With light loads I found myself checking the rear view to see if the trailer was still hooked, cause I did t feel the weight AT ALL. Retired now so sold business but kept the silverado to this day. Would like to pump up the 8.1 mildly in near future without pulling it. Any suggestions. Was thinking modify the intake, gasket port n polish the heads, headers, n maybe a cam if possible without pulling it out. I just don't have the needed space. One car garage w/ z06 n harley.
Yep, these are definitely excellent lifetime trucks. From what I have seen, many owners focus first on opening up the intake with aftermarket breathers and headers with dual exhaust. Getting into the engine takes a little more work, since they're are very few aftermarket companies offering high performance components for these. I do know I've seen some retrofitted with superchargers and intake/head/cam packages.
Hey Matthew sounds like a good setup. I have a 75 k5 4wd and I have a 8.1 with an Allison 1000 and a np263. I was thinking of going with a th400 and the original trans behind the 8.1. I also have a dana 60 and 14 bolt as well as the original axels. How do you like the setup with the 400?
Figure anywhere between $1500-$3000 depending on condition and mileage with core engines bringing less obviously. As far as crate engines go, these are pretty impossible to find at this point since they've been out of production for so long. I just happened to get lucky when I stumbled across this one featured in the video.
I can attest to the horse power and torque of the 496 8.1 I worked as a tow truck driver for a few years and the company I worked for used them in almost all their trucks most were factory propane fuelled or converted to propane but a few trucks were gas powered and the c7500 that I drove was a dream no problem picking up anything and climbing hills it sometimes felt like you were driving a giant Cadillac if you had a Car on the back heavy enough to dampen the springs in the back and it had no problem keeping up with traffic on the highway or accelerating from a stop light it wasn’t as fuel efficient as a diesel but maintenance was much cheaper than the diesel’s and replacing a blown engine with a rebuilt one was around $5000 and they sounded great
Had a choice in 2002 between this and the “new” Duramax...I chose this due to the legacy of this big block and reliability. Bought an 02 2500hd GMC with the Allison and 4.10 gears. Best decision I’ve made on a vehicle! Tons of power and torque and tows trailers like a diesel. I tow trailers at 80 mph over one of the largest mountain passes in the west. It used oil from the start which a new recalled intake gasket helped. Also had a faulty crank position sensor that didn’t throw a code. But other than that, 300,000 miles later and not one issue! Half those miles were towing a trailer. Unfortunately, it just gave up on me last week...p0300 code along with crank and cam position codes... I’m curious where you got this crate engine? Looking for options if I can’t get mine running...
Hey Micah, great testimonial. Like you mentioned, the reliability of this engine has everything to do with the legacy engineering put into the BBC since 1965. With proper maintenance, the reduced cost of operating one of these will definitely save you money over the long run. I happened to get lucky with this particular crate engine. The gentleman who bought it new had plans to put it in his Rolls Royce, but he never got around to it. I purchased it from the second owner who was planning on putting it in his boat, but he abandoned that idea when he figured out how expensive the prop drive system was going to be. The good thing about the 8.1 is there are quite a few out there since they were used in so many applications.
15 years ago I saw an ad in the newspaper ( how times fly ) just as the paper was delivered about 6 a.m. . I called real quick about a 8.1L for sale for $500.00 thinking it was a joke . It was real and the guy was a GM dealer mechanic that had replaced the engine under warranty and a bolt from either the crank or pressure plate ( can't remember for sure , it's been so long ago ) had gotten up and chipped a chunk of cast iron out of the block where the plug that seals the end of the camshaft . It wasn't leaking or even close enough to ever leak but GM did warranty the engine with a complete crate engine . I bought the engine over the phone and drove two hours to meet the guy during his lunch break . I was thinking it was a wasted trip all the way there knowing that either he had already sold the engine or there was a lot more damage than stated . He had the engine on the cherry picker and set it in my truck , i paid him and he told me how a bunch of his fellow mechanics had cash in their hands when he first showed up for work and that his word to save the engine for me was his word and if I didn't show up then he would sell it when he got back to work . I spread the word about the engine that afternoon when I got home and my phone was blowing up when I turned it on the next morning and I sold the engine before noon the next day for $1200.00 and a damn good old Arkansas country cafe lunch . I did notice numerous differences between the 8.1 and the 454's I was familiar with and learned later the guy that bought the 8.1 had a hell of a time dropping it in his 454 Chevelle . Great video sir .
Hey D, that was a nice score. The 8.1 is one of the worst kept secrets among the gearhead crowd, even though it's an engine that has been lost to time for a majority of casual car fans. From what I can see, the demand for them will stay consistent for a long time with the people that use them as the work horses that they are.
I have a 2001 3500 dually with a 8.1 with a Allison trans. and I have 280,000 miles on it and it is a pull monster. I've had a 20' bumper pull trailer with a 580C case backhoe on the back and never felt it back there. I pulled it about 50 miles..
Yep, the testimonials are everywhere about the pulling power of the 8.1. I'm pretty sure that 580 Case was well past the "recommended" tow limits for the truck, but like you said, it's like it wasn't even there.
I have a 2001 Chevy Silverado 4X4 HD and I love it.. runs great and my fuel mileage is about 15-20 mpg depending on how I drive it. When I'm on it hotdogging it she burns more fuel, about 8-12 mpg..
That was something I stumbled across while searching for parts to rebuild the 8.1 Yukon. There aren't too many 20 year old 8.1 crate engines left out in the wild😁.
2005 big block with Allison trans has a 6th gear lockout, you can buy a kit to utilize the overdrive gear. The intake manifold is baffled down to a small opening along with a small MAS change and replace these gain nice power and torque
Larry the owner of Raylar Engineering who's a very close friend of mine put an 8.1 in his 99 Vette close to twenty years ago, shortly after that he started Manufacturing his cylinder heads
Great breakdown of how things are different on these vortec motors. I have the 8.1 in my 2001 suburban 2500 and it has around 250,000 miles. Haven't had any internal breakdowns to date. You were so right in saying these motors are highly sought after, but they are also hard to find parts for too. One question because you seem to know alot about the different years of the vortec is about the throttle bodies. My 2001 has a throttle body, drive by wire, where wiring harness connects by 8-pin straight plug and I cannot find anybody, even aftermarket that sells throttle body with this connection. 2002 and up switched body style with an 8-pin plug that is more rectangular and connects on passenger side of body. I was hoping if somebody knew if I ever had to buy a new TB, can I switch to a newer model, with different plug config.? If so, how to I find out how to do a plug conversion? Would I have to switch cpu to a 2002 or newer. I may want to do some upgrades whenever I decide so rebuild, and this TB issue is a big pain. Any help would be appriciated.
Philip, I do believe that an upgrade to the 02 and newer style TB will require not only a harness but the Throttle Control Module and gas pedal as well. Let me check with some of my sources and I'll get back to you.
@@VetteSource its been a couple months since my last reply thanking you for your suggestions on my throttle body issue. Just curious if you were able to verify switching out gas pedal, control module and harness would allow me to switch to newer model throttle body. I still haven't found anybody else that can give me an answer on this.
After doing a little research it can be done but will require a repin of some of the connectors into the throttle body, TCM, gas pedal, and ECM. Not impossible, but not the easiest task either.
Thank you again for question. I have not yet found anbody willing to take this project on. Most people just say it can't be done. They just don't want to deal with the electronics of it and put their name behind it. I'm frustrated besause just a couple day ago, 3 times while my wife was driving to work, the truck went into reduced power mode. She looks at me and just says, fix it. I will keep you updated.
I have a 540 ci industrial version of this motor.plan to stroke and bore it to 621ci with conventional top end had to relocate some head bolts but not too bad
I have a 2002 a Alanche 2500. I would like to know where the #2 cylinder is located. It's showing a p0200 code. I replaced plugs and wires but it's still has a misfire. I would appreciate any help and input. I'm wanting to check the Injectors
I have 2 8.1s i am putting a 4l80 on the back but am having a problem with the converter fitting tight against the flywheel have you ran into that before?
Hey Don, I haven't but have you verified if your using the flywheel specifically made for the 8.1/4L80E? From memory it has a specific GM PN# and is rather pricey.
Hey Isaac, that should be a fun swap. It will have all kinds of power with the shorter wheelbase. As far as I know the RV 8.1's had the same rated power output. Other than cam, fuel injectors, and PCM programming most of the various applications had similar power ratings with the exception of the Marine HO engines.
@@VetteSource That's what I was thinking too it seems like a fairly easy swap at least in theory and I think they should've offered it from the factory as a Tahoe ss
Yea, it's not too stressful. I'd be willing to bet that the shorter wheelbase and lighter weight of the Tahoe had something to do with it not being offered from the factory.
Where there's a will there's a way However, I would would be prepared for quite a bit of engine bay and firewall modification to make this monster fit in the smaller space of the newer Corvette and Camaro.
Wow! Never knew GM made a 496 ci engine! What kind of HP can it make with a mild build…say a cam, maybe some head porting, headers, throttle body & intake manifold? Basically bolt on parts…
Hey Daniel, these definitely tend to become forever trucks. Like you, I have a 2000 OBS Crew Cab 3500 SRW with the Vortec 454 and a 2002 NBS Crew Cab Dy Dually with the 8.1 that will last me until the day I die.
I do believe I've seen a carburetored intake for the 8.1, but can't remember who the supplier or manufacturer is. The holes in the head are the coolant passages. It uses a different water circulation setup than the previous BBC generations.
PSI makes a big bro of this at 8.8L with piston coolers, some blocks are SAE. Dart made a 4.5 and a 4.75" crank, large valve iron heads, 4bbl dual plane intake so you could run a carb & dizzy if you wanted. 8.1\8.8s are tall deck motors, like gm truck blocks. Aftermarket BBC rods and piston combos can fit. OEM manifold was a bottle neck. HO Marine units had a bigger cam, minimal smog parts,,,,more HP.
Hey Glenn, thanks for the comments and information👍. I've seen the guys running these with the aftermarket mods and the power output can get pretty insane. I might try some of that with the 8.1 GMC 2500HD truck I'll be putting back together. For this engine I think I'll leave it alone since I don't want to throw too much power in the 8.1 Yukon that will be used by my wife most of the time😁.
I have a 02 suburban 496 and still outruns my newer 5.3. the 496 has 312,000 and has never slowed down. Nothing more than suspension, radiator etc. 312k on the original starter, coils, transmission, power steering pump etc. I wish it would give up so I can blue print and balance it and get even more power out of it!
I've never been able to find it myself. The only reason I knew about it was reading about it in a very old article. If you find it, feel free to share👍.
Great video, thanks for the info. I am currently rebuilding a Gen VII 8.1 from a 2006 Silverado and cannot find torque specs or head bolt pattern tightening diagrams. Do you have any suggestions for where to find that information? Thanks
Hey Justin. Even though it has LS architecture adapted to it the 8.1 is still a Big Block Chevy, so nothing from this engine will work on an LS engine and vice versa with the exception of the PCM/wiring and fuel injectors as long as you are running a high performance build that can handle the higher fuel pressure. It's pretty much a one-off kind of animal, as most of the pieces won't even work on the previous generations of BBC.
I've got a f350 crew cab and I.also have a 8.1 out of a motorhome with 17300 miles my 7.3 needs lots of tlc you know inj cups clutch fuel sys weak so guess what oddball motor swap I'm planning nothing. gets going more than someone telling me you can't do that wish me luck I'll keep you guys posted ps great video
You constantly say that it has to be paired with the Allison transmission I drive a 04 GMC 7200 and it is paired with a 5-speed manual and that engine is pretty tired is there any way that I can cheaply make it untired?
Belongs in the c4 with some good raylar aluminum heads, c3 big block headers will work for a regular big block swap into the c4, not sure about the vortec 8100, as you know it's an oddball, different heads etc.
Yep, I've contemplated what it would take to shoehorn one of these in between the frame rails of a C4. Maybe I should keep that as a future YT project idea.
@@VetteSource big block c3 headers will definitely work. Or even the stock manifolds. I'm sure you're aware of the Richard Holdener vids on the 8.1, or the guy from powerblock TV that turboed his 8.1, L.T. is his name.. in a c4 with a zf s6-40 transmission and d44 with 3.42 gears it would be a total BEAST! Probably get decent economy too. 411 ecu swap. Would require some research to keep the fuel economy display active, but it's been done. 400 rwhp and 500rwtq at a lazy 5000 or less rpm = the tpi gm should have released in the 85-91 c4
Yep, I completely forgot about the exhaust manifold interchangeability. Thanks for keeping me straight😁. I haven't had time to watch Richard's 8.1 video series, but going to try to carve our some time this evening. Thanks for the headsup👍
@@VetteSource I didn't know the suburbans had that option.. do you know which years came with the dual tanks ? Or if all of them can have the 2nd tank added ? I'm sure I can find the tanks somewhere .
Pretty sure it was all the 8.1 Suburbans and Yukons were equipped that way since the larger 34 Gallon tank from the 3500 trucks wouldn't fit on the 3/4 ton chassis. Let me know if you find any, I would be interested to see how the conversion goes.
Yes I can confirm that the 8.1 trucks had a smaller secondary tank above where the spare tire would sit under the frame which would put it around 38‐39 gallons. I haven't found any bigger tanks that would fit a 3/4 chassis. From what I read, GM added these secondary tanks as part of marketing scheme to advertise that you could still get around 300 plus miles on one tank without advertising that the tank was actually bigger to hit that range. However I will tell with how the fuel system is designed it's time consuming/pain to get both tanks full with sensitive pumps at the gas station.
I have seen people using the Rotella heavier weight in their trucks. For an 8.1 with a little higher mileage, it may be a good way to keep the oil consumption within tolerable limits.
Thank you for making this enjoyable video. Bought a used 2004 2500HD CC long bed LT with the 8.1L in 2005 with 19,500 miles. Was like new and paid $22,500 for it. The truck just turned 300k miles and has proven to be one of the top purchases I’ve made. Repairs: 1 coil pack, 4 sets of plugs, TPS replacement, 1 alternator, 1 master cylinder, all new brake lines, driveshaft carrier bearing,
Windshield washer pump, new AC compressor and I’ve had various electrical issues (none severe). Normal brake maintenance etc.. Have friends that have purchased 4 or more trucks in the time I’ve owned the 2500HD 8.1L and have not once felt the need to shop for anything else. I believe, in several ways, buying a new truck would be a downgrade.
glad you enjoyed. I agree with you, everytime I look at one of the new trucks, I end up taking one of my 8.1's on a day trip and remember why I have no interest in upgrading...
Love these engines. My 2002 burban 2500. Pulls like a champ starts every time. 10500lbs camper hooked up. Never misses a beat. 4l80e holds the power just just fine nice crisp shifts. 201000 and climbing. It’s a shame when something this reliable comes to an end.
Yep, definitely a powerhouse for the ages. Good thing I'm a believer in second chances😁. I should have it finished up and back on the road in the next couple of months.
What was the mileage when towing?
Most of what I hear states around 8-10 when towing depending on total weight and topography.
@@camscustombuilds I’d have to say 8mpg. But. I didn’t buy for fuel economy.
@@fk4191 neither did I. I have an 04 Burban w/122k, 4wd and can get 13 mpg when you pedal it. It sure is a hauler.
My 2004 Suburban tows a 12 ft cargo trailer all over the USA. 15 mpg on a good day. 250,000 miles, zero problems. If it had more gears it would get even better mileage.
Great ro hear. I'm getting closer to having this engine installed in my 04 Yukon, so I'm interested in what kind of towing mileage I'll see.
I have the 2001,
270,000 and it is still as strong as it ever was ,
Love the set up of the Trans and motor ,
Headers and a Big K_N Filter ,
Yep, I've heard they breathe much easier with those modifications
I bought a 2001 2500HD new from the dealer with the 8.1. It is still my daily driver and my work horse @ 326.000 miles. I had to put a cam sensor in at 100,000 miles but no other issues. The truck itself has been beat to hell and back but keeps going. I have a couple of small leaks from oil lines and it burns a TINY bit of oil since day 1. I expect to have this truck and engine for at least another 250,000 miles. Yes, it has the Allison and I love that thing too.
Yep, that seems to be the overall consensus from long term owners of the 8.1 equipped trucks. Long term reliability in a truck, especially if you're on the road or using it for business makes your life so much easier. Thanks for the testimonial👍. I'm looking forward to using my 8.1 as a daily.
Got a 02 avalanche with 8.1 bought it with 96k now has 286k has not skipped a bit beat and still pulls like hell I love it.
Now that's a testimonial! As much as some might complain about fuel mileage, these engines make up for in how long they will survive and keep working for you.
@@VetteSource i plan on rebuilding and doing some upgrades whenever she does go but until then just gonna keep on trucking
Yep, that's the way I would do it. Keep driving it until the wheels fall off.
A neighbor of mine just put one in an ASTRO van...! It was already LS swapped and not surprisingly because it's a GM product, it sold right in place of the LS with very minimal changes...! It's probably the fastest ASTRO van in Florida... Thanks for sharing... Keep up your awesomeness...!
Now that's hilarious. I'll bet he surprises quite a few people at the stoplights with that rig😁.
@@VetteSource When it hooks up...
I just bought my 1st 8.1 in a 2500 HD GMC Sierra and I fell in love on the test drive. Amazing how quiet it is and how smooth she rides. I’m the 3rd owner. Last guy had it for 3 years and an old man had it from the showroom floor before that and well cared for the whole truck.
I appreciate the information by the way. I had never even heard of it before looking at this truck.
No problem, glad to share. Sounds like you got a good one there. Enjoy it👍.
@ 8:20 - 8:25 = (Lost Foam Casting ). I have this Vortec 8.1L in my 2000 National Surf Side . It's perfect for my application . It's the next best thing to a Diesel pusher . Thanks for the Great post .
Hey Surf, thanks for the clarification. Glad you enjoyed the video👍.
I have two of these in my 2005 37’ Sea Ray. Great engines !
For sure, I can only imagine the power output of these bad boys on the open water👍
@@VetteSourceit would disappoint you. 😂. They only build them to about 375hp/450lb and the boat is 17,000lb. Boat cruises at 26mph @ 3400rpm and prob about 40mph at WOT. But the boat is sleek looking and looks like it would cruise at 50mph 😂 oh ya, and gets 1 mile per gallon at best. 😮
i can speak personally for this engine. i had one in a 2009 GMC c7500 and hauled GCWR of over 30k daily. had the 6speed manual trans and was geared very low. this engine spent most of its life at redline. i drove this truck with 75k on the clock for 3 years including a trip from St. Louis mo. to Fresno California. that's 4 days driving almost 12hr days and it topped out at 65 so it was pegged the entire time. the truck/engine never complained. stayed cool and kept running until we retired it at 80k and i was given a 2021 f750 with the 6.7, wish i still had that old gmc lol.
Thanks for the testimonial, Richard. It's one I've heard often about the 8.1's, and the regret once the owner/operators don't have them anymore. When you're using your truck for commercial purposes over the road, reliability is king, and the 8.1 has that in spades.
I really think you missed your calling with this vid. Great explanation and detail, it's like a show aired on the history channel for the 8100!! I rarely turn that bell icon on for any channel but I will for this one!
Brodi, thanks so much for the kind words. I greatly appreciate the positive feedback👍. I'll do my best to keep providing interesting content to watch.
Two comments about problems I’ve experienced with this engine… 1st glad you showed the back of the block. At about 90K miles I had the crank sensor fail and leave me in a Walmart parking lot. It’s not serviceable from under the hood, you have to reach up from underneath, around the bell housing and try to pull it out. In my 40+ years as a shade tree mechanic, I have never come this close to curling up and crying uncontrollably. I ended up having the truck towed to a local dealership for repair. At this point there were just wires coming out of the hole. When I asked the mechanic how he did it, he said “plenty of thread penetrating oil and a curved set of needle nose pliers”. A very frustrating and expensive learning experience.
Second on the list, on my truck the exhaust pipe crosses behind the oil pan by just a few inches. Not a problem unless someone tries to use an impact wrench to remove/install the oil drain plug. The hole has been stripped for a number of years now and I can’t get any of the typical oil change businesses to change my oil because they don’t want to deal with a vehicle with a temporary plug in the pan. It’s a bit of an irritation at times.
Other than these items, the engine is still running strong after 20+ years. Not too shabby
Hey Rusty, those are good points. Thanks for sharing👍. You're absolutely correct about the crankshaft position sensor. I had to remove it from the 3500 truck after I first reassembled it, and it was not a fun job, even with the extra space created with the factory 2" body lift. The aluminum oil pan is an interesting feature as well. It actually feels pretty solid, but I never thought about the oil drain plug stripping the threads. You may have already investigated it, but the new oils pans can be had for around $125 through rockauto or Amazon. Not too hard to change either once you drop the lower crossmember.
I had no idea about that crossmember. I’ll take a look. Thanks for the tip!
No problem, anytime👍
In our Motorhome I had the crank sensor fail intermittently.
Went to pull it ( easily to get at in this application )and it came out partly. We’ll with nothing to loose I have it a bit more ompf popped out. Lots of never seize on the new one.
2001 workhorse w-22 chassis.
I went through that too and it's a bitch on a big block. My knuckles were torn up by the time I was done.But ever since it has been very reliable ( besides the rear crank seal)
I have that engine in a 2003 motorhome, runs great and pulls hard.
Chevy definitely saved the best for last with this one.
Great video and yes very few people know about the 8100 Vortec. In my opinion and experience with these 8100's, they are the best ever made. I own a few 8100's and 7400's (all GMC duallies, Suburbans & Yukon XL) and my daily driver is a 2002 GMC Extended Cab dually 8.1/Allison with 4x4 on the floor and I'm close to 800k miles. The motor, transmission and axles have never been rebuilt or replaced. The only major part replaced has been the transfercase about 3 times but other than that, just regular maintance and minor parts it is needing that I have done myself. She is my baby and I take really good care of her always. Many people don't believe me about the mileage (especially diesel guys) and this truck is used to work hard and doesn't give up at all. I have always pulled with it all over Texas(my home) and a few more states and have done alot of traveling in it since the first day I bought her(15 years ago with 32k miles from the first owner like brand new😍) and she still pulls hard like a mean beast. I'm still searching for more to buy no matter the distance.lol Well I can go on and on but I really enjoyed your video and all the info is great and I'm looking forward to more videos and yes, I am a GM Big Block guy too👍Thats all I own since I drive🤠
Galdino, thanks for sharing. Glad to see see other 7400 and 8100 enthusiasts like myself. I too have a mixture of both trucks, with a 2000 SRW 3500 with 7400 Vortec that I've used as a daily driver for almost 20 years. These are well built machines, and like you mentioned will last forever if properly maintained. Im.in Texas as well, maybe I'll see you on the road one day👍.
@@VetteSource yes Sir hopefully one day we meet. San Antonio is my home but I like to take road trips all over Texas to find more treasures. Im looking forward to see more of your Yukon XL. Well stay safe and keep having fun👍
Will do, looking forward to it👍
I have an 2002 chevy crew cab dually 3500 with this motor. Bought it 2 yrs old. I still have it. Runs very well...no issues. It does consume some oil but nothing excessive or ridiculous. Plenty of power. I've pulled some heavy trailers and it's done well. It does use gas. 10 miles per gallon in city driving is the norm. Very dependable. Always starts and idles beautifully. Very quite and smooth.
Yep, I have the exact same truck I picked up last year to put back together. It sat in a shed with the engine and transmission laying beside it, with everything piled in the bed for several years. I did some mild prep work, put it all back together, and it runs exactly the way you describe. You have to really try to kill these things.
I've had my 02 ccsb Chevy HD with the 8.1 for 4 years now. I still absolutely love it. It has a custom tune, set up for 89 octane and gets 11 mpg all around average. With 4:11 gears and 285 tires I can manage almost 12 mpg empty on the freeway under 75mph. I pull several trailers but it's biggest impact is my 20' steel frame cargo trailer. It's a foot overheight and bucks wind like crazy. The truck pulls it easy but I average 7 mpg with that no matter how much weight is in the trailer. As far as oil consumption. I've found old school conventional 10-30 is best. I use maybe a quart between oil change. I ran a synthetic and a blend a couple times to try but experienced poor results using as much as 3 quarts between changes to keep the ol girl full and happy. Thanks for your video.
Hey MnR, thanks for the testimonial and feedback. Like you said, these are great trucks and with the 8.1 become family legacy type vehicles.
Awesome overview, great detail! I've got an 8.1 extended cab dually, and it pulls awesome. My only complaint is with the Torque Management system, which I intend to tune off shortly. The combo of this capable, simple engine in front of an Allison transmission makes it impossible to justify the cost of a new truck.
Hey Jeffrey, thanks for the comments. These are incredible trucks like you said, but the torque management system is a puzzling system. I am troubleshooting it on the 02 CC dually I rebuilt and it's driving me crazy. Who did you have perform the torque management delete on your truck?
i have an 01 2500hd and it has 180k miles i couldnt ever justify spening 90k on a new pickup as for 10k i can totally rebuild the engine and tranny which doesnt need it. love this truck
Yep, I believe this is one of those trucks that will always be viewed in many circles as the pinnacle of GM design and durability.
I have this engine with the 5 speed Allison transmission in my 2004 Fleetwood class A motor home. It's a 32 footer and weighs in at around 21000 pounds. Fully loaded with everything including the kitchen sink and pulling a Toyota camery it gets almost 8 MPG and never misses a lick. Strong and dependable, and in my opinion the best non diesel engine ever put in a class A. The Ford Triton V10 is more popular in the older rv's like mine but you have to push them above 4500 rpm to make the power the 8.1 makes at 3200 rpm. I also like the idea of an all cast iron assembly instead of the aluminum heads on a cast iron block like the Ford. If you are thinking of buying an older class A and have a budget of around 25k the Vortec Workhorse chassis is the way to go.
Great testimonial, thanks for sharing👍
Love mine. California to NJ in 50 hours. Never missed a beat.
That would be an awesome trip. I'm guessing around 350-400 gallons of gas. With today's fuel prices that ain't cheap👍.
Think I was just under 300 gallons for 28xx miles. Still, not a cheap trip. 11.2 - 11.8 @ 80 mph. 7000 truck with driver, 4.10 rear 75 series tire. So, stock basically. Lol
Yep, at least you were traveling in first class style👍.
@@VetteSource 80 east coming back. From salt lake city, all the way through to nebraska in the morning, i was driving through blowing snowstorm. O2 3/4 ton avalanche, worn out city tires on the rear, was playing the odds to get back home to my tire guy. Anyway, couldn't see the road most times, occasionally could draft a rig, or get in his eske for a few miles.
Auto 4wd, let the computer do the work, concentrated on steering and speed. Every highway gate I came up to in wyoming, I expected to be closed. Nope. Drove on. Ended up being about 600 miles of puckered seat cover.
Truck never wiggled, wobbled, or missed a beat. As my friend put it... you could have had slicks on the front, and she would have still tracked right. Mass. ❤ I've got 2 of these trucks. One, is a spare. Bought them both, because saw where truck prices are headed, as the dollar declines. It's the body style everyone skips, I'll take them all.❤ had 1440 lbs of tile tearout in the bed, the other day... wheeling it through rush hour traffic, like it wasn't even phased.
Can't do that, with the new half tons, without ending up with an 6spd neutral trans. 🤣
That's the kind of testimonial that keeps people interested in these bad boys. Did you happen to catch the video of the Chevy truck that got caught in the tornado and flipped over multiple times? As soon as it landed upright, the guy just drove off in it. Now that's tough😁.
I just purchased an '01 Sierra 2500hd sle with 217,000 for what I thought was a very reasonable price not knowing a whole lot about the 8.1 except that it is a big block gm. Have to replace a few things on it like lf brake hose and the entire rear bumper assembly because it spent most of it's life in OR then the last 60,000 in MN. A bit rusty. Found it in FL and boy does she purr. After hearing your testimonial and history overview, I'm MUCH happier with my decision! I love muscle and this truck has plenty to spare in stock form. An ox in pony clothing! Thanks for sharing your insight! Much appreciated.
Hey W, glad you enjoyed it. Now that I've been fortunate enough to acquire some of these 8.1's for myself, I'm sure they'll be with me for the rest of my days. Awesome powertrains for sure👍.
Just dropped this beast in my 84 c10!!!
Nice! That should wake up that square
body👍
@VetteSource oh yeah it sounds so good right now. Next is exhaust thinking 3" all the way out.
+1 for the 8.1, I daily one of these in an 01 suburban. Lots of fun confusing and astonishing people when I tell them just how huge the engine is. To touch on the oil consumption issues as far as I've experienced/read, these engines will consume more oil when run on the factory recommended 5w30. I've found my engine using noticeably less oil after switching to 10w30 for the summer months and I'm currently testing 5w40 for the coming winter.
That's good information. I'll have to try that out once I start daily driving these. It is funny to see the confused look on people's face when you mention how large the engine is. It was one of those options that many never noticed.
Whats your typical mpg ?
@@jimmymcclelland3727 around 8-10 in stop and go traffic, I'm sure with a couple mods, a tune and careful driving that number could be brought up a bit.
I bought a brand new 02 GMC Sierra 3500 Dually with a 8.1gas + Allison. From day 1 that motor would consume 1 qt of oil for every 1500 miles or so. It now has 175K on the odo.
About 2 weeks ago I installed a CA legal K&N FIPK before heading out from Los Angeles to Denver CO. I can feel the benefits from the K&N kit in the seat of my pants and interestingly enough the motor didnt use 1 drop of oil on the 2200 mile trip. My guess is the factory intake and PCV system generates a lot of vacuum and the open filter element of the K&N created a drop in vacuum in the crank case. I have always ran Castrol 20/50 oil. Also the fuel MPG has always been 9.5 to 10 MPG. I got 11.5 with a 1984 Goldwing in the bed and doing aprox 85 to 95 MPH on uphill grades.
I use 15/40 rotella! Dropped oil use to about 1 qt to 1000 miles
I bought a class B motorhome based on the Express 3500. The 8.1 is very smooth, and it loves running at 75-80.
Yep. I've heard they perform very well in the RV's👍
Great video, the 8.1 builds have jumped the last few years. Hope the pushes for a better aftermarket. The Chevy 2500 Avalanche the 8.1 was the only option. My first was a 1500 started towing bigger trailers and purchased the 2500 installed 456 gears. Love 8.1.
Thanks, glad you enjoyed it. These engines are legendary and I believe will be popular for many years to come👍.
What tire size were you running with 4.56 gears? I'm thinking of installing a set on my truck running 265/75/16 tires
@@user-wj9wq7mk4h I run the stock tire and rim. I like running 16's for the sidewall and less mass.. Craze is at about 1500 miles my MPG jumped. It likes 2200 rpm for best all round MPG. Went from no matter what it was 10 now is 12.5 to 13. I've never seen anything above 14 cruising now I've seen almost 16.
Bought my 2002 2500hd Silverado brand new. Now has 201,000 miles. Contiplating if I should do the timing chain. Right now truck is down for a whole new suspension. Almost done. Did a solid axle swap using 1979 Ford Dana 60 kingpin. 10 inch lift with 40's.
As far as problems I have had:
Crankshaft sensor went at around 38,000 miles. Common problem with these.
Air intake manifold leak throwing p0101 code. I actually drove on it like this for 8yrs. CEL would only come on during hard acceleration.
I had a exhaust manifold bolt break off in the head due to heater core hose dripping on it. Was able to repair it with a heli coil. Still holding up after 7yrs.
Oil pan gasket developed a leak. Replaced. But after doing the solid axle swap, if it leaks again it will be a breeze to do now.
Camshaft sensor went out. Engine would crank and crank until it started. Not too bad to fix this.
Yep, lots of good info contributed by long-term owners of the 8.1 trucks. Thanks for sharing. It looks like it's been a good vehicle for you👍.
I bought a 2003 gmc c6500 truck with an 8.1 Ltr with 124000 miles on it running on liquid injected propane. Now has 330000 miles on it. Just took a compression check to see if it was worth putting new injectors in it. 4 cylinders have right around 150 psi 1 cylinder at 148 psi and 1 cylinder at 161 psi. This is my work truck. It runs 6 days a week mostly city driving. Short runs all day long and once in awhile maybe a 50 to 100 mile run once a month sometimes well loaded. Unreal pulling power. Well worth putting new injectors in it. I am sure the rest of the truck will fall apart around that motor before it gives up. Only thing bad about it is if you think gas is poor fuel mileage, propane is half what gas is. But propane is cheap. the gross vehicle weight rating for the truck is 25900 and it is at its max often. Never has a problem pulling the weight.on the mountain roads of Oregon. I will run that motor until it dies but at the rate it going I think I will be First.
Hey Mark, thanks for the testimonial. Real world examples like yours are what keeps these engine in demand now and will continue to do so in the future. Glad to gear the truck has been such a valuable asset for you.
I’ve been using the Nug Block Chevrolet since early 80’s, if you take of it , it WILL take care of you. I never had one of these, it’s gotta be a Tough Nut. 👍
That's a great way to describe the 8.1, a tough nut👍.
I have been a fan of the big block chevy since i was a kid in the late 70's. my uncle had a Chevelle SS 396 L78 4-speed car and a flat bottom ski boat with a 454 LS6 crate engine in it. both were super fast. once i was able to drive i got a camaro with a 350 small block but my dad would never let me swap it out. after i got our of the air force i found a 71 Camaro ss 396. not the most potent 396 ever made, but once rebuilt it added a roller cam and got rid of all the smog just, that thing was unreal. consistent 11.7's in the quarter mile on radials. there is probably another .5 - .7 seconds in it if i were running drag radials or slicks. was always festinated with the 8.1L vortec big block. it had a lot of high performance potential with right cam and better after market support.
Hey Shad. Cool story, thanks for sharing. You and I are from the same generation of late 70s/early 80s. My fondest memories are of the BBCs prowling the streets like T-Rexs on the hunt.
Even though some of the power output of the newer generation small blocks is impressive, they will never match the sound and cool factor of a BBC with a solid lifter cam at WOT.
The 8.1 was an awesome send-off for the BBC, and I'm glad to have finally been able to acquire one to use on a daily basis. Of course, that's as long as I can keep the fuel cost from bankrupting me🤣.
@@VetteSource I know all about fuel cost... my 71 SS 396 get 10mpg. up hill, down hill, pulling a trailer, 70mph tail wind, doesn't matter... its getting 10mpg. but it will crush most modern cars, and even shocked a few Hell Cats that did not realize how fast a BBC Camaro can be.
Yea, it's always amusing to see that gobsmacked look on their faces when you walk all over them🤣.
I have a 2004 ‘Burb with this engine and I’ll never sell it. Pulls everything I have (up to an 8500# camper) and it gets the same mileage if I’m pulling or not. Beast.
Yep, it's definitely a "keep for life" vehicle. As much as I like the advanced tech and features of the new trucks, I'll keep my old, low-tech stuff😁.
I just picked one of these up from the pull your own part place for 225. Getting ready to drop it into my 93 2wd Silverado. And have a work/play truck
Man, that's a score right there👍. Google luck with the project and let us know how it's going.
@@VetteSource I grabbed a 6.0 truck engine and a Duramax the same day lol. All three the same price.
Yea, I see engines I want at these yards quite frequently but never have enough time to go back over and grab them. Glad to see somebody is getting good use of them👍.
@@VetteSource I've never seen that many good engines on the same day. My cousin and I pulled all three the same day. We took the radiator support bolts out. Cut the pretty rusty fenders right down the middle. Folded the clip up like a hood. Cut all hoses and wiring. Cut the frame each side. I reached back and got the bell housing bolts, motor mount bolts and cut the exhaust.
Now that's what I'm talking about👍. A Sawzall and a few basic tools will work wonders for retrieval of parts that would normally be hard to get to.
This is the engine driving my 2004 National motorhome in a 2003 GM Workhorse Chassis with an Allison 1000 Tranny.
Yep, I've heard they do an excellent job powering the RV rigs.
@@VetteSource From what I have heard, way better than the Ford V-10s, and the Allison is a beast.
Yep, I would agree.
I picked up a 8100 6500 topkick with an LPG Version a few months back with 147k miles on it, so I am hope for some good luck with it on my food truck
I think you'll be very pleased. Really great powertrains👍
great video more on the 8.1 please!!
Hey Robert, thanks for the feedback👍 I'll be sure to make a few more.
I really appreciate the review. Thank you
No problem, glad you enjoyed it👍
I have one swapped in a 2002 Sierra 1/2 ton regular cab short bed 2wd with a 4l80. It is the most fun daily I have ever drove. It is my baby.
Oh yea, I can only imagine the power output of the 8.1 combo in a half ton truck. Got to be fun on the street👍.
@@VetteSource yes sir! It now has a quadrasteer bed and spacers to fill the wheel wells. I have a full out turbo truck and I don’t care about it as much as the 8.1 truck haha. 😅
For sure, the turbo power is cool but there's nothing quite like the feel or sound of a BBC at WOT. Sounds like a couple of great trucks you're running👍
@@VetteSource yes sir, thank you sir. I the 30k I put into the rcsb turbo truck, is awesome, it’s great. However…. Push come to shove, the the turbo truck is gone waaay before the 8.1 rcsb. I will never be the fastest, I just want to build a truck that GM should have in 2002. The real SS. Thank you for your response
Glad to do it, nice talking to you. Have a great weekend👍.
Love my 04 GMC 2500HD 4x4 Ext Cab. 316,000 miles and counting. Transfer case has been the only issue. Replaced at 280,000 miles. Pulls as well as any Diesel I've ever driven with far less issues. I have beefed up the brakes and Suspension 4" life and pull 22,000# on the bumper. It has never been babied. It's kinda retired now, only gets about 5,000 miles a year on it pulling 2 of my heavy Antique JD (60 & 80) tractors to show & Tractor Pulls. If your ever in the Boise, ID area, chat me up.
Now that's a testimonial! I would agree that the old boy has earned his retirement😁.
@VetteSource yet like any Ole Draft horse, always ready for the next big job!
For sure👍
I currently tow a 5th wheel camper with an '04 Sierra with the 6.0. That engine does fairly well pulling 11K lbs. but grunts in the hills. I am now looking for something with more low-end torque and since I am not a diesel guy, I favor the 8100. The Alison trans is a bonus! But, trying to find one with a decent body and less than 200K is somewhat difficult. I love those Vortec engines!
Hey Brian, great name👍. For sure, the 6.0 is a great hauler and will get the job done for most applications. It's when you feel the extra "oomph" from the 8.1/Allison that you realize what you've been missing😁.
I agree with you, the Vortec family of engines, especially the big blocks are some of my favorite engines for pulling and reliability. I've been using my 454 Vortec as a daily for over 20 years.
@@VetteSource I am going to look at (buy) a very nice truck with the 8.1 tomorrow. Pretty happy that soon I can put the old reliable 6.0 to rest. When I weighed my truck and camper, the CGVW was 440 lbs over the max capacity of my 6.0. And that's without my generator.
Yep, that can be a problem. Sounds like it could be a great truck. Let me know how it goes.
I was lucky enough by chance to find for sale a 2001 Chevy CC dually 8.1L/Allison 4x4 with only 32,000 miles on it four years ago. Had it shipped to New England site unseen. It was titled to a courthouse in Florida and had a steel flatbed on it. Found a clean takeoff oem dually bed out of Texas and grabbed it. Still needs a paint job after years in the sun in Florida but a great running truck. Gas mileage not much less than my 2008 1500 5.3L. Kicked New England winters ass plowing the last few years. As far as the oil consumpsion goes, install a catch can system while blocking off the plenum under the intake manifold and problem solved. Spent years (5+) reading about and watching all I could about the 8.1 before finding this truck. Future classic! Edit: have a 2nd 2001 8.1L/Allison 4x4 164k truck for parts. Also grabbed by chance, can't go wrong there!
Hey Larry, thanks for sharing your 8.1 truck story👍. It sounds similar to my experience with these great trucks. I always wanted one, and finally acquired a 2002 CCLB dually that had been disassembled, than found an 8.1L 2004 Yukon 2500 XL with a blown engine. Then I stumbled across a 2001 GMC 2500 extended cab needing an engine. I'm close to having the first two trucks back on the road, then will start in on the 2500 shortly.
Just bought an 8.1 out of an 03 Avalanche to swap out my 6.0 from my 02 2500hd 4l80 4.10s , from everything I've researched should be a pretty easy swap . There is a book , Chevy 8.1 Vortec 496 performance manual on Amazon $25 , if you have an 8.1 buy this book , tons of good info .
Great information, Brad. Thanks for sharing👍
I had no idea this book existed and I just ordered it! Thanx
Yep, definitely a great resource to have👍.
Just got a 2001 Suburban with 76k mi. with the 8.1....so excited!
Sounds like a great find that will be sure to give you many years of reliability and use👍.
I own a Bertram 31 with 2 of these 8.1’s and I love them!!!
Wow, and just when I think one 8.1 is enough....😁.
At 235k on my 02' Silverado ext cab long bed 8.1 w/ Allison 5spd. Love the effortless torque and simplicity of the engine. I've had cam sensor, maf dtcs and burns a little oil but besides that solid engine.
Thanks for the testimonial. The general consensus is that the GEN VI and VII BBC's are pretty much bulletproof unless you just outright abuse them. Even then most of the time they'll survive👍
There is an intake manifold upgrade most anyone can do for some free horsepower. You have to pull the intake off and cut the bottom off the intake manifold. There is a plate casted into the manifold inside that you can cut out and it will make right after the throttle body all the way to the back of the intake 50 % larger. You then need to weld the outer plate you cut off to gain access back on. The factory intake manifold stops flowing air at around 4000 RPM, This modification will allow much more flow and a smog inspection station will never know you did it.
Cool hack, thanks for sharing👍
Yeah Raylar Engineering does it as well for their stroker kits
👍
Just bought a 2002 3/4 suburban. 4 grand. And want clean. Mostly Rocker panels rusted out a little, only a knock sensor code. Runs nice so far
Yep, if you can keep the body from rusting away from underneath you, it will last for many years👍
THANK YOU FOR THE LOW DOWN ON THE MOTOR / VERY HELPFUL / I LEARNED A LOT THANK YOU
No problem, glad you enjoyed it👍.
I had two of these motors in 37 ft searay for 10 years. Never a problem with heavy use. Compression was the same as when I bought the boat after 10 years.
Great testimonial, thanks for sharing. These engines definitely take some abuse in marine applications👍.
8.1s in trucks were also available with the zf6 speed manual along with the allison 5 speed
Yep, and from what I've been seeing the ZF equipped 8.1's command a pretty high premium. Thanks for sharing the information.👍
These things are great. A gen 6 cam slips right in and all you'll gotta do is change it to a gen 6 firing order in the ECU. Monster engine with monster power potential.
Yep, love the BBC engines. Excellent powerplants👍
This engine would deliver a steady 300hp for thousands upon thousands of hours.
Absolutely, other than the normal oil consumption you see with all Chevy BB's, there's really not one thing to dislike about this powerplant.
Gah - a brand new 496 Big Block Chevy! You lucky dog !
Yea, I was quite thrilled to find this one.
I know of several 8.1s with 400-600k miles all still run great. With 4.10s and a Allison in a 2500hd they pull just as good as a diesel
yep, GM really wasn't kidding when they referred to it as the diesel alternative. Loads of power and none of the gas mileage😁.
I got one 2003 silverware I’m keeping mine thanks for sharing
No problem, glad you enjoyed it👍
My auto tech class had one of these, It was a seized motor that my class took apart and actually learned on, however the other classes spilled the fluids and put a bunch of components inside of the engine along with food and pencils
That sounds about right with an auto shop class. I remember in HS shop class, we received a brand spanking new 1989 Chevrolet Caprice Brougham. Still had the window sticker in it and 3 miles showing on the odometer. Rather than be allowed to learn something from it, the teacher wouldn't even let us tear it down or reassemble it. Instead, it sat around as a static display with the teenagers hanging out in it during class. I don't know which one is worse, but it sure seemed like a waste of a good learning tool.
Thanks for the information, very informative video. I just bought a 2002 3500 crew cab with the 8100. And yes the gas mileage is less than desirable and yes it does have an oil consumption issue. I have an issue on the # 8 cylinder fouling the plug. I’m hoping it’s a valve guide seal as it smokes badly on start up sometimes. It also has a periodic loud squeal after stopping at a red light and then goes away. I believe it’s a vacuum leak somewhere and it could be contributing to the spark plug foul. I bought the truck to pull my 24 ft inclosed Racecar trailer with a 3000 lb race car and tools air compressor generator etc. it does a good job. I’ll tear into it soon and figure out the oil foil and squeal.
Thanks for the feedback, glad you enjoyed it. I have the same truck as yours, and enjoy using it for my over the truck as long as i can justify the fuel expense with the current prices🤪.
Even with the few minor issues you're describing the great thing about the 8.1 is that it uses all the next generation LS fasteners and gaskets which makes it incredibly easy to tear into for inspection and repair.
I have a savana 3500 with that engine , best mileage has been 12 mpg , doesn't smoke , knock , or leak any oil . My van has 372000 miles on it .
Now that's a testimonial. You definitely don't see the 8.1 vans around much very more
I still run my '03 Silverado 2500HD to this day after all these years pulling our large 5th wheel trailers. Current 5th wheel is close to 14k lbs. Fuel mileage is nothing to brag about but this is a very large engine with little design given to saving fuel. In town fuel mileage is going to be little over 8mpg on average and close to that towing in all conditions. Unloaded on the highway could average ~13mpg if given enough flat roadway. But it really pulls well and that's why we still use it, well that and new trucks are not given away. I'd say we've got our money's worth.
That's the general consensus with the 8.1 trucks. Getting your moneys worth and then some. Wouldn't trade mine for the world. Thanks for sharing👍.
Got a 2005 ,GMC 2500 8.1 VORTEC ,ALLISON TRANSMISSION ,CREW CAB, LONG BED 4 WHEEL DRIVE ( ABSOLUTLEY LOVE IT ) HAD IT ABOUT 3 YEARS NOW , IT'S STOCK ,BUT A BRUTE , IF I WANT SOMETHING MOVED OR TOWED IT'S READY & CAPABLE ,BEST TRUCK FOR TRUCK STUFF I HAVE EVER OWNED
JUST TURNED 144,000 MILES ( GET R DONE )
MY BUDDIES SAY TOU'LL BE DAM LUCKY IF YOU CAN MOVE THAT , GUESS I AM LUCKY !
I HAUL CARS ,SCRAP STEEL ,LUMBER , YOU NAME IT , SIT BACK LISTRN TO THE AWSOME BOSE STEREO , SET CRUISE ,& TOW HAUL ,& JUST DRIVE !! SOULDN'T TAKE 2 OF THESE NICE NEW SHINEY PLASTIC TRUCKS FOR IT , THIS TRUCK IS THE REAL DEAL ! WAS LUCKY MAN THAT OWNED A CABINET SHOP OWNED IT , FOR HIM & HIS WORKERS TO GET TO JOB'S ,HE OWNED ,HE DROVE ,HE MAINTAINED TRUCK ,HAD A 18 FOOT LONG ENCLOSED TRAILER FOR CABINETS ,ETC , INTERIOR & ALL GREAT
A/C COLD ,EVERYTHING WORKS FLAWLESS ,
REALLY IMPTESED , LOVE THE ALLISON TRANSMISSION & WHEN IN TOW HAUL IT HELPS HOLD BACK WHEN SLOWING DOWN , ONLY FUTUTE PKAN , I WANT TO PUT DUAL EXAUST ON IT !
OTHERWISE LET IT EAT !! I PASS THESE NEWER TRUCKS ALL THE TIME STRUGGLING EITH A CAMPER ,OR TRAILER LOADED ,FRONT END LOOKS LIKE YOUR ON ONE OF THOSE HUMPD HUMPS AT A DRIVE IN MOVIE .( LOL ) WHEN IT SNOWS I FILL UP A LARGE COFFEE MUG & THERMOS & HEAD OUT
REALLY JUST TO RIDE , BUT I DO USUALLY TAKE MY GEAR & MAKE SOME GAS MONEY PULLING PEOPLE OUT , I REMEMBER ONE GUY OFF ROAD ABOUT 30 FEET WHERE HE HAD DUG & SPUN & SLIDE DOWN ,HOOKED EVERYTHING UP READY TO PULL , HE SAID YOU GOT IT IN 4 WHEEL DRIVE DON'T YOU ? SAID NOPE HASN'T BEEN IN 4 WHEEL ALL MORNING & I BEEN THE ONLY SET OF TRACKS ON MOST ROADS , I SAID I WILL WAIT & SEE IF I NEED IT
A LITTLE WHEEL SLIP AT FIRST , THEN WITH SOME FEATHERINGBOF GAS FOR OPTIMAL TRACTION ,UP & OUT CAME HIS DODGE HEMI RAM ,IT WAS IN 4 WHEEL DRIVE , HE WAS AMAZED, UNHOOKED DROVE OF STILL IN 2 WHEEL DRIVE ,OH DID I MENTION 8INCHES OF SNOW ON GROUND ,LIGHT SMALL FLAKE SNOW FALLING ,HAD SNOWED ALL NIGHT !
LOVE ME A WORK TRUCK ,& GOT ONE !!
Hey Gary, now that's a testimonial! 20 plus year old truck that makes you money while your out just cruising around. I'll have to save your story for everyone to see👍.
One more thing. I did this swap even though people said it wouldn't work. The 11.5 aam diff was very bad so I replaced it with a 14 bolt corporate. Paid 100 bucks for it.. lol. Same 4.10 gears to match the front. Which to me is one of the best diffs on the market. 40 years with only a few modifications...The only difference is you need a longer driveshaft. Everything else swaps. The only downside is you loose 1 grand towing capacity. Since the corporate is about 200lb lighter than the aam.
good information, thanks for sharing.
1. Oil consumption: mine was using oil and my mechanic pulled the intake bolts one at a time cleaned the bolt and the bolt hole then put sealant on the bolts and it stopped the oil consumption and fouling my plugs.
2. They are known to have problems in the 2001-2003 models with the crankshaft position sensor which can cause the engine to stall while moving but usually will start right back up, run ruff intermittently.
Good info Larry, thanks for sharing👍.
I got a very nice 2001 Silverado 2500 hd with this monster engine, it IS a Duramax Killer! I truly love my truck and in my opinion the 8.1 is the best truck engine ever built by GM !
I would agree. Over the last few years people have figured out just how powerful and reliable this engine actually is, which has kept the value of the trucks and engines pretty high.
The issue with calling it a Dmax killer is the dmax can make 650hp and 1000ft/lbs AND get 20+ MPG. I do love these engines tho and will be building one for a race truck soon
@@TMar129 Well, since I got it back from Raylar, it IS a Duramax KILLER! Pushing over 800 HP! Lol
Yea, I think it comes down to a matter of preference overall. I've seen the power of the Duramax, but for a more casual over the road puller, it has always made more sense for me to utilize the gas big block haulers.
Lots of industrial backup generators use this engine turbocharged and made to run on natural gas, or propane. We have one at my job. It's a big Ingersoll Rand
Definitely. The other 8.1 project truck I put together last year was actually run on propane for many years.
Purchased 02 2500hd w/ the 8.1 n the Allison trans. as a leftover in 03. Only have 145k miles.. first yr dealer replaced the booster.. otherwise with regular maintenance n an Xtra qt of 5 30 oil between oil changes, I'm xtremely happy with it. Using g it as a cement work truck , it was regularly pull heavy trailers with front loader on it with NOOO PROBLEMS. Always impressed as the Allison shifted going up n down hills with heavy loads. With light loads I found myself checking the rear view to see if the trailer was still hooked, cause I did t feel the weight AT ALL.
Retired now so sold business but kept the silverado to this day. Would like to pump up the 8.1 mildly in near future without pulling it. Any suggestions. Was thinking modify the intake, gasket port n polish the heads, headers, n maybe a cam if possible without pulling it out. I just don't have the needed space. One car garage w/ z06 n harley.
Yep, these are definitely excellent lifetime trucks. From what I have seen, many owners focus first on opening up the intake with aftermarket breathers and headers with dual exhaust. Getting into the engine takes a little more work, since they're are very few aftermarket companies offering high performance components for these. I do know I've seen some retrofitted with superchargers and intake/head/cam packages.
I've got an 03 8.1litre, infront of a TH400/NP203/NP205, with Dana 60F, and a 14 bolt, w/5.38 gears. All sitting in a 1973 K10 shortbox.
Hey Matthew, i've been seeing those conversions. Very cool setup and loads of rock crawling and pulling power I'm sure.
Do you have any videos posted of it?I'd love to check it out
Hey Matthew sounds like a good setup. I have a 75 k5 4wd and I have a 8.1 with an Allison 1000 and a np263. I was thinking of going with a th400 and the original trans behind the 8.1. I also have a dana 60 and 14 bolt as well as the original axels. How do you like the setup with the 400?
My 2002 Avalanche 2500 has the 8.1 with 265.000 miles, runs great and will pull any think i hook it to, loves ice and snow also.
Yea, I've heard the 8.1 Avalanches are quite fun due to the reduced weight.
Yes they are, i own 2, 2002 8.1 2500, and 2003 5.3 1500 and they both get the same milage, buy way different power, lol@@VetteSource
How much is one of these engines used if you don't mind sharing that information
Figure anywhere between $1500-$3000 depending on condition and mileage with core engines bringing less obviously. As far as crate engines go, these are pretty impossible to find at this point since they've been out of production for so long. I just happened to get lucky when I stumbled across this one featured in the video.
I can attest to the horse power and torque of the 496 8.1 I worked as a tow truck driver for a few years and the company I worked for used them in almost all their trucks most were factory propane fuelled or converted to propane but a few trucks were gas powered and the c7500 that I drove was a dream no problem picking up anything and climbing hills it sometimes felt like you were driving a giant Cadillac if you had a Car on the back heavy enough to dampen the springs in the back and it had no problem keeping up with traffic on the highway or accelerating from a stop light it wasn’t as fuel efficient as a diesel but maintenance was much cheaper than the diesel’s and replacing a blown engine with a rebuilt one was around $5000 and they sounded great
Mark, great testimonial. Every time I'm on the road with my 8.1, I feel the same way. It's like cruising along in a very powerful Cadillac😁.
Had a choice in 2002 between this and the “new” Duramax...I chose this due to the legacy of this big block and reliability. Bought an 02 2500hd GMC with the Allison and 4.10 gears. Best decision I’ve made on a vehicle! Tons of power and torque and tows trailers like a diesel. I tow trailers at 80 mph over one of the largest mountain passes in the west. It used oil from the start which a new recalled intake gasket helped. Also had a faulty crank position sensor that didn’t throw a code. But other than that, 300,000 miles later and not one issue! Half those miles were towing a trailer. Unfortunately, it just gave up on me last week...p0300 code along with crank and cam position codes...
I’m curious where you got this crate engine? Looking for options if I can’t get mine running...
Hey Micah, great testimonial. Like you mentioned, the reliability of this engine has everything to do with the legacy engineering put into the BBC since 1965. With proper maintenance, the reduced cost of operating one of these will definitely save you money over the long run.
I happened to get lucky with this particular crate engine. The gentleman who bought it new had plans to put it in his Rolls Royce, but he never got around to it. I purchased it from the second owner who was planning on putting it in his boat, but he abandoned that idea when he figured out how expensive the prop drive system was going to be.
The good thing about the 8.1 is there are quite a few out there since they were used in so many applications.
I have this motor, my first 8.1 L has 45,000 miles on it, 2000 Chevy 2500hd, great BBC gas motor, though I prefer my 7.5 BBF motor.
Just wait until you realize how dependable it is and how long it will last😁.
15 years ago I saw an ad in the newspaper ( how times fly ) just as the paper was delivered about 6 a.m. . I called real quick about a 8.1L for sale for $500.00 thinking it was a joke . It was real and the guy was a GM dealer mechanic that had replaced the engine under warranty and a bolt from either the crank or pressure plate ( can't remember for sure , it's been so long ago ) had gotten up and chipped a chunk of cast iron out of the block where the plug that seals the end of the camshaft . It wasn't leaking or even close enough to ever leak but GM did warranty the engine with a complete crate engine . I bought the engine over the phone and drove two hours to meet the guy during his lunch break . I was thinking it was a wasted trip all the way there knowing that either he had already sold the engine or there was a lot more damage than stated . He had the engine on the cherry picker and set it in my truck , i paid him and he told me how a bunch of his fellow mechanics had cash in their hands when he first showed up for work and that his word to save the engine for me was his word and if I didn't show up then he would sell it when he got back to work . I spread the word about the engine that afternoon when I got home and my phone was blowing up when I turned it on the next morning and I sold the engine before noon the next day for $1200.00 and a damn good old Arkansas country cafe lunch . I did notice numerous differences between the 8.1 and the 454's I was familiar with and learned later the guy that bought the 8.1 had a hell of a time dropping it in his 454 Chevelle . Great video sir .
Hey D, that was a nice score. The 8.1 is one of the worst kept secrets among the gearhead crowd, even though it's an engine that has been lost to time for a majority of casual car fans.
From what I can see, the demand for them will stay consistent for a long time with the people that use them as the work horses that they are.
Very torquey motor. I special ordered my 4x4 with a 6 speed manual and twice broke my mounts. I'm on my 3rd motor mount replacement.
Yep, those ZF6 equipped trucks are hard to find.
Marine 8.1 is the best out there
Yep, I agree. Feel very fortunate to have stumbled across this engine.
@@VetteSource will last longer then automotive marine is the real VP
Yep, that's what I'm hoping. I told my kids they can cart me off to the retirement home in this truck, I'm not planning on it going anywhere.
@@VetteSource love it brother !!
I have a 2001 3500 dually with a 8.1 with a Allison trans. and I have 280,000 miles on it and it is a pull monster. I've had a 20' bumper pull trailer with a 580C case backhoe on the back and never felt it back there. I pulled it about 50 miles..
Yep, the testimonials are everywhere about the pulling power of the 8.1. I'm pretty sure that 580 Case was well past the "recommended" tow limits for the truck, but like you said, it's like it wasn't even there.
I have a 2001 Chevy Silverado 4X4 HD and I love it.. runs great and my fuel mileage is about 15-20 mpg depending on how I drive it.
When I'm on it hotdogging it she burns more fuel, about 8-12 mpg..
Yep, it's definitely hard to keep your foot out of it with all the torque of that 496👍.
Where did you pick up this crate motor??
That was something I stumbled across while searching for parts to rebuild the 8.1 Yukon. There aren't too many 20 year old 8.1 crate engines left out in the wild😁.
2005 big block with Allison trans has a 6th gear lockout, you can buy a kit to utilize the overdrive gear.
The intake manifold is baffled down to a small opening along with a small MAS change and replace these gain nice power and torque
good information, thanks for sharing....
Larry the owner of Raylar Engineering who's a very close friend of mine put an 8.1 in his 99 Vette close to twenty years ago, shortly after that he started Manufacturing his cylinder heads
That must have been a monster on the streets.
@@VetteSource it is, it has a 6-speed manual transmission and he still owns it
Very cool. How does the T56 stand up behind it?
@@VetteSource I think the Transmissions done okay but I believe he had a torque tube failure
For sure, those become problematic when you start adding HP and Torque.
Great breakdown of how things are different on these vortec motors. I have the 8.1 in my 2001 suburban 2500 and it has around 250,000 miles. Haven't had any internal breakdowns to date. You were so right in saying these motors are highly sought after, but they are also hard to find parts for too. One question because you seem to know alot about the different years of the vortec is about the throttle bodies. My 2001 has a throttle body, drive by wire, where wiring harness connects by 8-pin straight plug and I cannot find anybody, even aftermarket that sells throttle body with this connection. 2002 and up switched body style with an 8-pin plug that is more rectangular and connects on passenger side of body. I was hoping if somebody knew if I ever had to buy a new TB, can I switch to a newer model, with different plug config.? If so, how to I find out how to do a plug conversion? Would I have to switch cpu to a 2002 or newer. I may want to do some upgrades whenever I decide so rebuild, and this TB issue is a big pain. Any help would be appriciated.
Philip, I do believe that an upgrade to the 02 and newer style TB will require not only a harness but the Throttle Control Module and gas pedal as well. Let me check with some of my sources and I'll get back to you.
thank you so much, any suggestions will help.
@@VetteSource its been a couple months since my last reply thanking you for your suggestions on my throttle body issue.
Just curious if you were able to verify switching out gas pedal, control module and harness would allow me to switch to newer model throttle body. I still haven't found anybody else that can give me an answer on this.
After doing a little research it can be done but will require a repin of some of the connectors into the throttle body, TCM, gas pedal, and ECM. Not impossible, but not the easiest task either.
Thank you again for question. I have not yet found anbody willing to take this project on. Most people just say it can't be done. They just don't want to deal with the electronics of it and put their name behind it. I'm frustrated besause just a couple day ago, 3 times while my wife was driving to work, the truck went into reduced power mode. She looks at me and just says, fix it. I will keep you updated.
I have a 2003 2500hd, 8.1 .130,000 miles.clean as f*ck. Good truck. Pulls great.love tha Allison.
Yep, these are keeper for sure👍.
any advice on installing new fuel injectors on my '04 8.1? thanks from Texas
I actually have a video detailing the fuel injectors and rail swap. You can see it here -
ruclips.net/video/ch2gLA1OJvY/видео.html
I have a 540 ci industrial version of this motor.plan to stroke and bore it to 621ci with conventional top end had to relocate some head bolts but not too bad
Yep, there's quite a bit of stuff you can do with this engine. Sounds like it will be a monster👍.
I have a 2002 a Alanche 2500. I would like to know where the #2 cylinder is located. It's showing a p0200 code. I replaced plugs and wires but it's still has a misfire. I would appreciate any help and input. I'm wanting to check the Injectors
I have 2 8.1s i am putting a 4l80 on the back but am having a problem with the converter fitting tight against the flywheel have you ran into that before?
Hey Don, I haven't but have you verified if your using the flywheel specifically made for the 8.1/4L80E? From memory it has a specific GM PN# and is rather pricey.
Im swapping one into my tahoe and I found one out of an rv do these make the same power as the ones you find in the trucks
Hey Isaac, that should be a fun swap. It will have all kinds of power with the shorter wheelbase. As far as I know the RV 8.1's had the same rated power output. Other than cam, fuel injectors, and PCM programming most of the various applications had similar power ratings with the exception of the Marine HO engines.
@@VetteSource That's what I was thinking too it seems like a fairly easy swap at least in theory and I think they should've offered it from the factory as a Tahoe ss
Yea, it's not too stressful. I'd be willing to bet that the shorter wheelbase and lighter weight of the Tahoe had something to do with it not being offered from the factory.
Would this engine fit in a late model Camaro or Corvette?
Where there's a will there's a way
However, I would would be prepared for quite a bit of engine bay and firewall modification to make this monster fit in the smaller space of the newer Corvette and Camaro.
Wow! Never knew GM made a 496 ci engine! What kind of HP can it make with a mild build…say a cam, maybe some head porting, headers, throttle body & intake manifold? Basically bolt on parts…
Hi will the 8.1 vortec heads fit bbc 454
Nope, they have coolant passages built I to them that feed from the water pump so they won't interchange.
I had a 2002 Avalanche 2500 with the 8.1L traded it for a bigger bed but that thing would tow a 30' boat like it was a tool box
Yep, the towing power of the 8.1 is pretty epic. Just don't expect to pass many gas stations😁.
@@VetteSource no kidding, it claimed 10/15mpg but it was 7/12mpg on a feather foot.
Yep, as much as I love the engine and drivetrain, you better plan accordingly for fuel costs when you take that trip😁.
I've got a 2001 3500 extended cab Sierra 3500 with the 8.1 and still have my '78 Silverado dually with the original 454.
Hey Daniel, these definitely tend to become forever trucks. Like you, I have a 2000 OBS Crew Cab 3500 SRW with the Vortec 454 and a 2002 NBS Crew Cab Dy
Dually with the 8.1 that will last me until the day I die.
Can these be converted to carburetor, i also noticed it has holes in front of heads ?
I do believe I've seen a carburetored intake for the 8.1, but can't remember who the supplier or manufacturer is. The holes in the head are the coolant passages. It uses a different water circulation setup than the previous BBC generations.
PSI makes a big bro of this at 8.8L with piston coolers, some blocks are SAE. Dart made a 4.5 and a 4.75" crank, large valve iron heads, 4bbl dual plane intake so you could run a carb & dizzy if you wanted. 8.1\8.8s are tall deck motors, like gm truck blocks. Aftermarket BBC rods and piston combos can fit. OEM manifold was a bottle neck. HO Marine units had a bigger cam, minimal smog parts,,,,more HP.
Hey Glenn, thanks for the comments and information👍. I've seen the guys running these with the aftermarket mods and the power output can get pretty insane. I might try some of that with the 8.1 GMC 2500HD truck I'll be putting back together. For this engine I think I'll leave it alone since I don't want to throw too much power in the 8.1 Yukon that will be used by my wife most of the time😁.
I have a 02 suburban 496 and still outruns my newer 5.3. the 496 has 312,000 and has never slowed down. Nothing more than suspension, radiator etc.
312k on the original starter, coils, transmission, power steering pump etc. I wish it would give up so I can blue print and balance it and get even more power out of it!
Now that's a testimonial right there👍. Like you, I love the longevity of the engines, but always love any opportunity I get to tear into one.
Anybody found the comparison video he mentioned ford, dodge v10 vs Chevy 8.1? I can’t find it but would love to see it.
I've never been able to find it myself. The only reason I knew about it was reading about it in a very old article. If you find it, feel free to share👍.
Great video, thanks for the info. I am currently rebuilding a Gen VII 8.1 from a 2006 Silverado and cannot find torque specs or head bolt pattern tightening diagrams. Do you have any suggestions for where to find that information? Thanks
Here's a forum post with all the relevant torque specs for the engine -
www.pirate4x4.com/threads/8-1l-torque-specs.928052/
Do parts from a LS swap onto it? Just curious since you mentioned so much was adopted to it
Hey Justin. Even though it has LS architecture adapted to it the 8.1 is still a Big Block Chevy, so nothing from this engine will work on an LS engine and vice versa with the exception of the PCM/wiring and fuel injectors as long as you are running a high performance build that can handle the higher fuel pressure.
It's pretty much a one-off kind of animal, as most of the pieces won't even work on the previous generations of BBC.
I've got a f350 crew cab and I.also have a 8.1 out of a motorhome with 17300 miles my 7.3 needs lots of tlc you know inj cups clutch fuel sys weak so guess what oddball motor swap I'm planning nothing. gets going more than someone telling me you can't do that wish me luck I'll keep you guys posted ps great video
Sounds like a fun project. Let us know how it goes. Glad you enjoyed the video👍.
You constantly say that it has to be paired with the Allison transmission I drive a 04 GMC 7200 and it is paired with a 5-speed manual and that engine is pretty tired is there any way that I can cheaply make it untired?
When you say it's tired, what kind of symptoms is the engine showing that would make you feel it's getting worn out?
it just drags *** feels like a lack of horsepower unless that's how the engine is on the bigger truck@@VetteSource
Belongs in the c4 with some good raylar aluminum heads, c3 big block headers will work for a regular big block swap into the c4, not sure about the vortec 8100, as you know it's an oddball, different heads etc.
Yep, I've contemplated what it would take to shoehorn one of these in between the frame rails of a C4. Maybe I should keep that as a future YT project idea.
@@VetteSource big block c3 headers will definitely work. Or even the stock manifolds. I'm sure you're aware of the Richard Holdener vids on the 8.1, or the guy from powerblock TV that turboed his 8.1, L.T. is his name.. in a c4 with a zf s6-40 transmission and d44 with 3.42 gears it would be a total BEAST! Probably get decent economy too. 411 ecu swap. Would require some research to keep the fuel economy display active, but it's been done. 400 rwhp and 500rwtq at a lazy 5000 or less rpm = the tpi gm should have released in the 85-91 c4
Yep, I completely forgot about the exhaust manifold interchangeability. Thanks for keeping me straight😁.
I haven't had time to watch Richard's 8.1 video series, but going to try to carve our some time this evening. Thanks for the headsup👍
is there anyway to get a bigger gas tank on one of these trucks? it seems like they only make aftermarket diesel tanks now
I'm sure you could probably find a way to retrofit the dual tank setup from an 8.1 Suburban/Yukon XL. Finding the tanks might be the problem.
@@VetteSource I didn't know the suburbans had that option.. do you know which years came with the dual tanks ? Or if all of them can have the 2nd tank added ? I'm sure I can find the tanks somewhere .
Pretty sure it was all the 8.1 Suburbans and Yukons were equipped that way since the larger 34 Gallon tank from the 3500 trucks wouldn't fit on the 3/4 ton chassis.
Let me know if you find any, I would be interested to see how the conversion goes.
Yes I can confirm that the 8.1 trucks had a smaller secondary tank above where the spare tire would sit under the frame which would put it around 38‐39 gallons. I haven't found any bigger tanks that would fit a 3/4 chassis. From what I read, GM added these secondary tanks as part of marketing scheme to advertise that you could still get around 300 plus miles on one tank without advertising that the tank was actually bigger to hit that range. However I will tell with how the fuel system is designed it's time consuming/pain to get both tanks full with sensitive pumps at the gas station.
Great info, thanks for sharing. I wonder if the GM part # is still floating around out there to still do that conversion.
I have a 2004 chevy silverado 2500hd with a 8.1L in my truck so my question is can I use Rotella T4 oil 15w 40 in my truck.
I have seen people using the Rotella heavier weight in their trucks. For an 8.1 with a little higher mileage, it may be a good way to keep the oil consumption within tolerable limits.
PSI (Power Solutions International) made this engine as well for big forklifts or big industrial equipment.
That's correct, I've head people talking about the PSI version, but haven't looked into them that much. I believe they are 8.8L engines.