I'm with you LT, regardless if it was worth it or not. The fact that you can and you did the swap is just cool and honestly why not, right. I enjoy watching this build solely due to the fact that it is not a high end build that costs you your first born, and is totally achievable in your own garage.
@@LawrenceTolman you are for sure better than the guys on there now. I know I am a master mechanic watching a show for normal people but, dang they play up the tiniest thing.
I’ve always sorta-kinda wanted to build a short box standard cab 2WD ‘SS 496’ (throwback to the ‘90s 454 SS trucks) half-ton Silverado with the 8.1L drivetrain. Of course it’d be black, with custom decals in the same font and everything as the old 454 SS trucks, I think it’d be cool. I figure the 8.1 with just an intake, headers, exhaust, and a tune should be kinda a rocket with stock reliability forever, vs. building a 5.3. No way would it fit in my Colorado, though, and it’s genuinely fast with a factory 5.3 and factory 4.10 gears.
I think it's pretty cool that LT takes the time to read and reply to so many comments. Also, he doesn't get defensive and blast a bunch ppl taking up for the 5.3l. Obviously 5.3's are cheap and awesome, no better bang for the buck, etc. This 8.1l swap is super cool and waaay more unique.
I have a Yukon XL 2500 8.1 with 4.11 gears. Aftermarket tune, catback exhaust and new high flow cats. I just did a 300 mile round trip and got just a tick over 12mpg, premium. Still totally worth it. This engine is a gas diesel. So much torque available right off of idle.
4:27 does a killer burnout & in the same breath, “ I can’t figure out for the life of me why this truck is wearing out rear tires!” Guy fukken rocks! 👍😎
I have an 01 2500hd with the 8.1/allison combo. Upgraded form a 1/2 5.3 Towing is night and day. I can tow 8k and the 8.1 rarely if ever comes out of overdrive. Loads of torque. When it downshifts towing it only runs about 2900 rpms. I love it. Only problem I haven't figured out is how to drag a gas station behind me yet. 10 mpg town/hwy.
Thank you for making these videos! There is not much content covering the 8.1. These are such badass engines. I drove a UPS truck with 8.1 Allison combo, it took a beating every day for years. I have an 8.1 suburban and really looking forward to seeing what you do with ugly truck.
8.1 is very reliable and easy to maintain. Mpg not great but when comparing I bought my 04 hd2500 almost 6 years ago with 40k for 23500$ shipped to my front door all fees included (1500$) shipping. Oregon to Texas. The same truck with dmax at time was at least 10k more plus ttl here. I love it. Had to put fuel pump on it because of how it was stored prior to purchase. But only valve cover gaskets since. 140k now. No regrets. I have 33s allison and recently 4.56 gears. Still 10 mpg combined driving. Sorry so long just wanted to inform non owners. Myself and 3 friends all daily 8.1s. Mine is lowest miles. One friend over 300k never out of truck only gaskets, plugs, wires.
410s -430s is good, 3200 stall, cam. All it need lolol hell I do 2700 rpm in my 454 slammed obs crewcab with 410s with a 4l80e. Long trip I can do 300 on a tank. But city highway I do about 240 per tank. About 16-17mpg combined ill never sell mine... love the swap and truck man!! Stay different !
Love ya LT! Been watchin you since you first started on PB. Definitely have matured and are more comfortable as a video host. Keep up with it, looking for more Truck Tech.
Great truck mod and what a interesting swap to a big block. Looking forward to future mods. Your knowledge from HP tv is a added bonus. Thanks for sharing. Fan from Sydney Nova Scotia
Loving this series! Keep up the good work, you clearly know what you're doing. I own a 2001 Sierra ext cab 5.3. I recently just added 2inch lowering shackles and it got rid of the infamous GM rake. I'm digging the 4/6 drop on yours! I'm probably not gonna turbo mine but will put a stronger trans, camming it, and perhaps swapping gears in the rear end. Thanks for the inspiration!
@@LawrenceTolman i'd do it all at once. the ring gap and compression might be an issue. maybe a cam to work work with the turbo would be wise though i don't think that would be needed to just get it going. the stock valve springs and rockers might need to be addressed to. the springs are weak, and bearings give out if you get too crazy on ls engines. it sounds like you might though i know the 8.1 is a bigger block and i think it's not actually a "ls engine". i love the idea of a sleeper btw awesome idea. got ideas for my little ranger.. was thinking a 302 built up but not sure. that ls in 3/4 ton is nice and anything in that family with a cam..
Not sure if the engine is stock or not, but I'm pretty sure there are aluminum heads out there that'll fit the 8.1, not sure if Mark IV big block heads fit, maybe LSX heads if the LSX block is closer to the 8.1 block. Some aluminum heads and a cam to match would really wake it up and give it a wider rpm range if you'd ever like to wind it out. I think a n/a build would be sick.
Ah, the peeling clear coat on the hood and roof is an all to familiar sight lol but I'm starting to think my 02 Silverado might be the "uglier truck" :(
There are a lot of ways to get those numbers from a 5.3 to start.. but the difference will come later with add on’s as the bar is raised, so will the separation from the two.
I knew someone here in California that had one of those 8.1s in a long bed dually and he put a Gear Venders Overdrive box behind the Allison and towed triple axle horse trailers in the winter and new 5th Wheel RVs all summer and last I heard there was over 600,000 miles on the stock drivetrain. Other than the usual alternator, waterpump, and fuel pump here and there the only issues were intake gaskets (twice),plastic intake manifold (once),crankshaft sensor(twice), rear main seal and the high pressure line on the hydoboost system(both at once) but with that Allison/GearVenders combo he was getting decent fuel mileage and only replaced the brake pads once about every 80,000 miles!!!!!
I think 14-15 mpg is a bit optimistic, even with overdrive. The 8.1's were notorious gas guzzlers when new. 3000 rpm at highway speed is pretty high IMO. However, as a fun, joy ride type toy, it's a great ride! Also, great production quality in this video. Very well done. Reminded me of a episode of Stacey David's Trucks show. 👍
That truck is 1000 lbs lighter and the rotating mass is greatly reduced too. Lighter axles, small rear, light driveshaft, tiny brakes, light rims and tires. That makes a big big difference. You also can get 1.5-2 mpg with an exhaust that isn't covering half the exhaust ports and fighting you the whole way to the tailpipe. The 8.1 exhaust not only cost it power, but also mileage.
Curious what to did to the harnesses. Was it plug and play or did you have to repin stuff? That wasn’t mentioned. But got me really curious I want a 8.1 or a 454 lol
@@LawrenceTolman going off of what William stated, you should do a segment on what kind of aftermarket support there is for this engine. Would be good information to know.
Can this conversion pass the California smog laws? And be smog legal? Its a great alternative that replacing stock 475,000 mile motor thats in my 04 silverado crew cab short box.
I have an 04 with an 8.1 and 4.10 gears and love it. I pull a 32ft camper and my boat with it and it's an excellent tow rig. The mpg sucks but I also have never needed to fork out thousands of dollars (just for parts mind you) to replace head gaskets or injectors on a Duramax. That motor is extremely reliable, Mercruiser offered the package for boats and I remember reading that they tested the 496 at wide open throttle for 500 continuous hours and it held together. That being said someday I'm still going to sell my truck to my dad once I find a clean low mileage cat eye Duramax with no rust 😂 I look forward to this build!
Yeah people hate them cause you can't throw a bigger turbo on them and dump a bunch of black smoke out the back like a Duramax or a Cummins. They might have more fans if they were optional in half tons, but gas big block heavy duty trucks, that really hasn't been a popular thing since the 80's/early 90's, the Dodge Cummins pretty much changed the world 30 years ago away from gas engines in heavy duty pickups.
I'd love to put an 8.1 in my 96 Buick Roadmaster sedan. The LT1 does okay, but it really needs a lot more. I only get 12-16 MPG anyway, so I might as well have a bigger engine
Just doing an 8.1 swap pulled the 5.3 used the wiring from the 8.1 and ecm getting a fuel pump relay that's clicking turns over but won't start. Should I go with the 5.3 harness and ecm. What did you do to do drive by wire as my 5.3 was drive by cable.
I stumbled across a company called Raylar Engineering in my research of this very same swap for my 03 Silverado that actually makes what appears to be good parts for these 8.1 Vortecs, forged stroker cranks and aluminum cnc ported heads could make that a whole lot more fun
Hello lt need a bit of your expertise on my 2007 Yukon it has an la engine keeps reading low pressure oil even after I changed the oil pressure sending unit , have u have any good advice on this thk you sir
theres a chance the gauge is reading correctly, and you do have low oil pressure. supposedly the o-ring that goes between the pickup tube and the oil pump can shrink over time and cause low oil pressure. If it were me, I'd make sure to remedy and low oil pressure issues asap because the engine is at stake.
I can tell you from experience that truck would be more fun and feel faster with a much higher rear gear. As in 3.08s or 3.55s. With 3.08s it would feel like a rocket ship on the highway and still have plenty out of the hole on street tires. Very low gears in a truck like that would only be useful if pulling a heavy load like a large camper or towing a race car. Low gears are also great for smaller high reving engines
I had a 2001 Sierra with the 6.0L V8 and 4L80e/4L85e. Was a stout truck and then the 6.0 wanted to blow. Had plans to swap a built 8.1L and a built Allison 6 speed but ended up having to lose the truck. Currently got a 94 F-150 that I plan to swap a BBF V8 and have an adapter housing made for the Ally 1000 with the SAE 2 or 3 bellhousing. I'm choosing a built Allison because why the heck not... The C4/C6 and TKO crap is SO OLD......So here's what I got in mind. -Built, Stroked and Sleeved 460/7.5 (stroked to 501/8.2) -MSD Direct Ignition -Jon Kaase HEMI heads -Built Allison 1000 6-Speed -Stand Alone TCM (Hoping I can set my shift points to 6400) -Sterling/Dana axle conversion -4.10 Gears
@@LawrenceTolman If the idea with the Allison goes wrong, I may be able to contact Performance Automatic OR Browell Bellhousings to see if they can make a bellhousing to fit on a chopped Ford 6R80 trans. I don't wanna give up on the 6-Speed auto conversion since I'd like to have a double overdrive on an old engine.
You won;t need to go to that high of an RPM with the Allison. I have a 8.1/Allison and the gear ratios are perfect. Just find the right rear end gear so as the transmission shifts through the gears it stays in the power band. On an 8.1 it's like 3600rpm, my 8300lb truck moves right out from a stop all the way up to 85(I don;t take it past that, it's a stock 2500HD not a race car) There really is no comparison to older transmissions or even the 4L80's, the Allison is a game changer and you can alter your entire build around it. It's like having a T56 that shifts itself, the ratios are just spaced right and are all pretty close.
Let’s say you had a stock stall, 4l80e with say 3.13 gears or so for a daily driver 8.1 swap. Think that would get ok economy? Like at least 12 city 16 highway if you didn’t romp it? Always wanted a big block half ton
it might get a little better mileage, but with a 4l80 and those gears, it would be a dog out of the hole, and you'd be putting your foot into it a lot just to get moving (which uses a little more fuel).
So I got a 2005 8.1 and it has the Allison as stock.. but can I put a transmission from a 6.0 2500 of the same year? Or what's the best economical way to go I just need the truck to work and daily drive everything else is perfect
you have a blown Allison transmission? You can surely swap from an Allison to a 4L80e, it will just take some creative wiring and some adjustments in the computer.
@@LawrenceTolman what are only after I R and it turned it off and turned it back on if I turn it on let it warm up and drive it the whole vehicle drives perfect..
Its hard to find a 2500 with the 8.1 these days. it only shows me 22 trucks on autotrader (with 4wd selected). So next best thing would be getting a 2500 with a 6.0 and swapping it to an 8.1. However, I notice that it is also difficult to find a 8.1 engine and tranny combo for sale on ebay (or any other website)... Sucks, im graduating soon and will be getting employed right off the bat and would like to finally upgrade to a better truck. Always wanted an 8.1...
I have an old carburated 460 big block out of an 80's E-350 RV I want to stuff into my ugly 2002 F150 once I kill off the bone stock 4.6 modular that's currently in it. After the engine swap I want to cage and back half it. I'm going the prerunner route rather than a street truck. I wanna be able to hit a curb doing 80mph and keep going! =^D I need about 10k to 15k worth of long travel suspension components though, and a few years to build it. I'm getting the engine for free off my step brother though, so thats a very good start to this crazy project of mine.
@@LawrenceTolman Check your tire clearance, I’ve seen a tire Spaghetti like that it was because the tire was rubbing against the wheel well when accelerating/or carrying to much weight.
I had a 02 Avalanche 2500 4x4 with the 8.1l it was 373 geared and I had folks with 6.0 and 6.2 trucks ask me what in the hell do you have under that hood we cant keep up!...so yes the 8.1l is a total different ball game!..mabe a game changer!
Question please, was the Helwig rear swaybar worth installing? I have a 2010 Chevy Silverado 4x4 (all stock suspension) and was wondering if this swaybar would be beneficial for towing and hauling. Any info would be helpful and thank you in advance!
I’m sure you know this but if you’re gonna turbo it, you can definitely reuse your stock bottom end, just add ring gap. Especially if that engine has like 100k plus miles of daily driving, everything’s happy and working together (rods, pistons, crank, etc) and can take quite a bit of punishment. For instance the 5.0 sbf I’m swapping into a ranger, the stock gt40p pistons and rotating assembly will take more power than the block will as long as the rings are gapped properly (shooting for 500 to the tire with a mild ish buildup and turbo) so I’m sure your 496 can take some lickin
im on the fence about it honestly (opening up the gap). I know its a good idea, but mainly because I do plan on building the engine to hold 1,000+ within the next year it would be 2x the work for a temporary short term solution... but we'll see what happens
@@LawrenceTolman well if you're going all out and have the budget, of course go with forged. But I know of a ton of stock bottom end engines holding ridiculous amounts of boost with just ring gap. A buddy of mine had a 351w from an 89 f250 with twins on 24 lbs making over 1000 on the stock bottom end and it held for a long time. Wasn't even the pistons that gave up in the end. Main bearing grabbed the crank at 6500rpm and thats all she wrote. Those junkyard motors can surprise ya lol
the intake is a little restrictive, and there are some mods you can do inside to remove them. and yes, there are plenty of cams available. it would be fun to do a NA build first for sure
Well, I hope my 5.3L never needs replacing, but if it does, this confirmed my decision to drop an 8.1L in. My worries then are the 4L60E and G80 diff in the rear😆
yes, any LS computer and wiring harness will work, but the wiring needs to be modified slightly (check out my wiring video). I did the first start up with the 5.3 tune, but I did flash in an 8.1 calibration afterwards
the front would be the same as the K1500, the rear might depend on if there's any crossmembers or anything that would be in the way of going too low... but you should be able to use the same flip kit as for a silverado. Just don't know if the axle has enough room to go that low
What transmission you think i can use on my 1997 silverado C1500 with the 5.7 to try to upgrade just a little bit i love the truck but is can a slow....
unless you plan on putting in a lot more power the 4L60 is the way to go for simplicity sake, and has a better gear spread than the 4L80. But, if you want to make a lot more power the stronger 4L80 might be a swap to consider
Hey where are you filming? I noticed the license plate is Maury county TN where i used to live but the landscape looks more like the four corners than middle TN. Any love the channel.
It's a good bang for the buck truck. I'm closer to $5K on my swap, but I changed the transmission, had to source brackets for the Squarebody swap, and did headers and a segment swap on the PCM for the 4l80e. But....Big Block! For comparison, you cannot get into an 8.1 2500HD even with 200k+ miles for under $12k, and....Big Block.
Respect no doubt bad ass built we are here in this car and truck game to do orginal things go fast have fun and love what we do if your gonna whine about fuel mileage then your in the wrong game when your building hotrods fuel means nothing and if you can't afford the gas then you shouldn't be building hotrods power is what its about and originally and fun I love what you did here keep up the good work man damn rite
For the money I would turbo the 5.3. But big blocks have a cool factor that can't be matched. One more thing. You blow up the 8.1 those aren't super easy to find. 5.3 on the other hand are everywhere for cheap. Stock 5.3 with a decent turbo setup then just swap in another 750 motor when she goes.
Iv got a stock 05 gmc sierra with a 5.3 and has 20 inch gmc wheels from a newer truck. My truck roasts the tires just fine and honestly from flat footing it does it better and has a better smoke show. Not sure what 5.3 you have lol. Love the look of the truck tho. I'd like to lower my truck since its a 2wd about like yours.
I did a 5.3 to 6.0 with h/c/I in my 1500 silverado. I haven't gotten it dynoed so I cant say what power it makes. But after seeing your videos, if I could do it again I'd 8.1 swap it, dont get my wrong. The 6.0 is great and fun but 496 is just so much cooler. And I can tell you I have wayyyy more then $3000 total into everything in my truck so the 8.1 swap seems to be alot better of a budget build. Not to mention depending on your area or what kind of deal you can find changes the price. My 6.0 in the same situation as your 8.1 was only $1350
I used to own a 8.1, but gave it to my old man. He tells people it gets 18 mpg. 10 on the highway and 8 in town! 🤣
Lol! That's kinda how my truck is. Pass every damn thing on the road, except for the gas station!🤣😂lol
Best comment of 2020
Hahaha that’s a good one
That's about what mine gets. I can squeeze 10 in town but only if you drive like a grandpa
Hahaha
I'm with you LT, regardless if it was worth it or not. The fact that you can and you did the swap is just cool and honestly why not, right. I enjoy watching this build solely due to the fact that it is not a high end build that costs you your first born, and is totally achievable in your own garage.
it was kind of cool to do it at home with no exotic parts and more or less basic tools
This dude has the most soothing demeanor of any car channel I’ve ever seen
This guy seems like he would be a good mechanic for horse power tv or something.. he had that look and voice.
I think he would be good on the truck show...
He even has a TN license plate, Horsepower Tv is filmed in TN.
@@LawrenceTolman 😂😂🤘🏻🤘🏻 when you know you know 🤷🏼♂️😂
@@LawrenceTolman LOL they don't know....
@@LawrenceTolman you are for sure better than the guys on there now. I know I am a master mechanic watching a show for normal people but, dang they play up the tiniest thing.
> 1L of displacement per cylinder. Imagine if it was a single cab.
Done a few single cabs...
Imagine that 8.1 in a single cab s10 or colorado. Would have a real hard time keeping the tires planted
I’ve always sorta-kinda wanted to build a short box standard cab 2WD ‘SS 496’ (throwback to the ‘90s 454 SS trucks) half-ton Silverado with the 8.1L drivetrain. Of course it’d be black, with custom decals in the same font and everything as the old 454 SS trucks, I think it’d be cool. I figure the 8.1 with just an intake, headers, exhaust, and a tune should be kinda a rocket with stock reliability forever, vs. building a 5.3. No way would it fit in my Colorado, though, and it’s genuinely fast with a factory 5.3 and factory 4.10 gears.
@@ejmarkle60 yc0 77789inches hide 0zfzup
JE as47 was
i just did a mk4 454 in my single cab 91 , with an open diff lmao about the same hp level (holley sniper ,long runner intake and long tube headers)
Best part of all this is you are bringing to light an engine offered by GM that not many people know about! Keep at it!
thanks! i do like the more obscure and off the beaten path stuff
Keep 'em coming LT. Not a truck guy, but like how you talk through and show one of the most overlooked parts of a swap...the dang wiring harness.
thanks! i try and show every step along the way
I think it's pretty cool that LT takes the time to read and reply to so many comments. Also, he doesn't get defensive and blast a bunch ppl taking up for the 5.3l. Obviously 5.3's are cheap and awesome, no better bang for the buck, etc. This 8.1l swap is super cool and waaay more unique.
I have a Yukon XL 2500 8.1 with 4.11 gears. Aftermarket tune, catback exhaust and new high flow cats. I just did a 300 mile round trip and got just a tick over 12mpg, premium. Still totally worth it. This engine is a gas diesel. So much torque available right off of idle.
4:27 does a killer burnout & in the same breath, “ I can’t figure out for the life of me why this truck is wearing out rear tires!”
Guy fukken rocks! 👍😎
I have an 01 2500hd with the 8.1/allison combo. Upgraded form a 1/2 5.3 Towing is night and day. I can tow 8k and the 8.1 rarely if ever comes out of overdrive. Loads of torque. When it downshifts towing it only runs about 2900 rpms. I love it. Only problem I haven't figured out is how to drag a gas station behind me yet. 10 mpg town/hwy.
yeah, they're thirsty
You are the Richard Holdener of truck building. Keep up the good work!
well thank you! those are some big shoes to fill...
Thank you for making these videos! There is not much content covering the 8.1. These are such badass engines. I drove a UPS truck with 8.1 Allison combo, it took a beating every day for years. I have an 8.1 suburban and really looking forward to seeing what you do with ugly truck.
I've seen a couple of your videos before, but after watching this one I swear that we live close to each other.
possible, I'm on the west side of Utah lake
@@LawrenceTolman I'm about 15 minutes north of you then.
8.1 is very reliable and easy to maintain. Mpg not great but when comparing I bought my 04 hd2500 almost 6 years ago with 40k for 23500$ shipped to my front door all fees included (1500$) shipping. Oregon to Texas. The same truck with dmax at time was at least 10k more plus ttl here. I love it. Had to put fuel pump on it because of how it was stored prior to purchase. But only valve cover gaskets since. 140k now. No regrets. I have 33s allison and recently 4.56 gears. Still 10 mpg combined driving. Sorry so long just wanted to inform non owners. Myself and 3 friends all daily 8.1s. Mine is lowest miles. One friend over 300k never out of truck only gaskets, plugs, wires.
they are very reliable from what I've read and heard
I've always wanted someone to do this... Glad to see you knocked it out
it was fun! and not that hard of a swap either
@@LawrenceTolman I'm gonna have to look into it.
I always wondered about those 8.1’s, glad you chose it
It’s a cool platform
@@LawrenceTolman I just came about an 8.1 that came out of a boat. Which is already cam'd. This makes me want to put it in my 2000 chevy really bad.
@@danking5382 do you have any of the marinizing parts for sale. if so let me know
Need to do a torque per dollar comparison, that truck is bad ass.
that would be a good idea
A 8.1/transmission and everything else that goes to the engine can be had for under 4k
Also love that you ran the numbers and said what you paid. Love it!! Thanks for this series
Smiles per gallon out of that 8.1 and thats what matters. Can't wait for the next phase.
plenty of smiles driving it
410s -430s is good, 3200 stall, cam. All it need lolol hell I do 2700 rpm in my 454 slammed obs crewcab with 410s with a 4l80e. Long trip I can do 300 on a tank. But city highway I do about 240 per tank. About 16-17mpg combined ill never sell mine... love the swap and truck man!! Stay different !
glad someone out there understands!
Love ya LT! Been watchin you since you first started on PB. Definitely have matured and are more comfortable as a video host. Keep up with it, looking for more Truck Tech.
I appreciate that! It was a learning curve for sure
I’d love to have off road truck with an 8.1 and Allison.
bulletproof combination
Great truck mod and what a interesting swap to a big block. Looking forward to future mods. Your knowledge from HP tv is a added bonus. Thanks for sharing. Fan from Sydney Nova Scotia
Thanks for watching! Yes, have learned a lot from them
This is a great swap. Thanks for the info and detailing the minor issues with it. Great channel
Thanks for watching!
I can’t wait for more vids on this build!
making some more as we speak
Loving this series! Keep up the good work, you clearly know what you're doing.
I own a 2001 Sierra ext cab 5.3. I recently just added 2inch lowering shackles and it got rid of the infamous GM rake. I'm digging the 4/6 drop on yours!
I'm probably not gonna turbo mine but will put a stronger trans, camming it, and perhaps swapping gears in the rear end. Thanks for the inspiration!
sure thing!
This thing would be a monster even with LOW boost!
gonna limit it to 5-6 pounds probably until I build the bottom end. they say 550hp or so is the limit for the stock pistons
Would love to see you focus on making more N/A power before you boost it. But either way I’m still gonna watch it!
@@LawrenceTolman i'd do it all at once. the ring gap and compression might be an issue. maybe a cam to work work with the turbo would be wise though i don't think that would be needed to just get it going. the stock valve springs and rockers might need to be addressed to. the springs are weak, and bearings give out if you get too crazy on ls engines. it sounds like you might though i know the 8.1 is a bigger block and i think it's not actually a "ls engine". i love the idea of a sleeper btw awesome idea. got ideas for my little ranger.. was thinking a 302 built up but not sure. that ls in 3/4 ton is nice and anything in that family with a cam..
@@blueovalfan23 The Vortec 8100/496 is not an LS.. That'de be wishful thinking.. Hahaa
@@blueovalfan23 weak stock bottom end cant take much boost
This is a super sick swap, and def one of a kind. I'm gonna sub just for the turbo big block content in the future, I mean who could say no to that?
I know, right?
And not to forget: worthy acoustics, finally 😉
I am absolutely in love with the 8.1
they are such a fun engine
Not sure if the engine is stock or not, but I'm pretty sure there are aluminum heads out there that'll fit the 8.1, not sure if Mark IV big block heads fit, maybe LSX heads if the LSX block is closer to the 8.1 block. Some aluminum heads and a cam to match would really wake it up and give it a wider rpm range if you'd ever like to wind it out. I think a n/a build would be sick.
yeah, a company called Raylar Engineering specializes in 8.1 stuff, and they have heads, cams, stroker kits, and more
Ah, the peeling clear coat on the hood and roof is an all to familiar sight lol but I'm starting to think my 02 Silverado might be the "uglier truck" :(
yup, classic GM paint
And I thought only the white gm paint only peels lol
When ya swapped the PCM from black box to 0411 did the key fob to open the doors still work along with the AC, and the 4x4?
There are a lot of ways to get those numbers from a 5.3 to start.. but the difference will come later with add on’s as the bar is raised, so will the separation from the two.
got that right
You should do the same thing, but with a Quadraster truck, That'd be pretty sweet.
ive never even driven a quadrasteer rig, i think that would be pretty cool
I knew someone here in California that had one of those 8.1s in a long bed dually and he put a Gear Venders Overdrive box behind the Allison and towed triple axle horse trailers in the winter and new 5th Wheel RVs all summer and last I heard there was over 600,000 miles on the stock drivetrain.
Other than the usual alternator, waterpump, and fuel pump here and there the only issues were intake gaskets (twice),plastic intake manifold (once),crankshaft sensor(twice), rear main seal and the high pressure line on the hydoboost system(both at once) but with that Allison/GearVenders combo he was getting decent fuel mileage and only replaced the brake pads once about every 80,000 miles!!!!!
I think 14-15 mpg is a bit optimistic, even with overdrive. The 8.1's were notorious gas guzzlers when new. 3000 rpm at highway speed is pretty high IMO.
However, as a fun, joy ride type toy, it's a great ride!
Also, great production quality in this video. Very well done. Reminded me of a episode of Stacey David's Trucks show. 👍
That truck is 1000 lbs lighter and the rotating mass is greatly reduced too. Lighter axles, small rear, light driveshaft, tiny brakes, light rims and tires. That makes a big big difference. You also can get 1.5-2 mpg with an exhaust that isn't covering half the exhaust ports and fighting you the whole way to the tailpipe. The 8.1 exhaust not only cost it power, but also mileage.
I’m glad this came across my feed!!
Liked and subscribed!! I like this kinda stuff!
Awesome! Thank you!
@@LawrenceTolman I would like to know average MPG though
That is just a cool truck right there. The turbo build is gonna be great. Can't wait to see how it goes
Curious what to did to the harnesses. Was it plug and play or did you have to repin stuff? That wasn’t mentioned. But got me really curious I want a 8.1 or a 454 lol
For me the biggest issue with the 8.1 is the lack of aftermarket support.
yeah, its certainly not as well supported as the LS world
@@LawrenceTolman going off of what William stated, you should do a segment on what kind of aftermarket support there is for this engine. Would be good information to know.
Plus aftermarket parts r expensive $$$ for 8.1 which is basically a bbc with ls electronics..
I have a 2001 2500 hd 4x4 with a 8.1 and I get 14 on the highway and 12 in town it has a 4.10 gears on 35 x12.5 x 22s
not bad at all for a big block on a heavier 4x4
Can this conversion pass the California smog laws? And be smog legal? Its a great alternative that replacing stock 475,000 mile motor thats in my 04 silverado crew cab short box.
Like your videos, but your 14 to 15 mpg estimate seems optimistic, particularly with the gearing
ive got an 8.1 in a 2004 gmc wrecker i have, and when i am done with the wrecker, that 8.1 is going into my 1970 cadillac deville convertable for sure
That looks so much better! Keep the paint!
I have almost zero paint and body skills so thats the plan haha
Also I have 4x4, crew cab, steel flat bed, full front end replacement. 8100 lbs empty.
I've been really interested in this swap thanks you've opened my eyes so much
I have an 04 with an 8.1 and 4.10 gears and love it. I pull a 32ft camper and my boat with it and it's an excellent tow rig. The mpg sucks but I also have never needed to fork out thousands of dollars (just for parts mind you) to replace head gaskets or injectors on a Duramax. That motor is extremely reliable, Mercruiser offered the package for boats and I remember reading that they tested the 496 at wide open throttle for 500 continuous hours and it held together. That being said someday I'm still going to sell my truck to my dad once I find a clean low mileage cat eye Duramax with no rust 😂 I look forward to this build!
no question, a diesel is superior for towing a lot, but they are a lot more expensive to purchase and maintain, so a big block is a good substitute.
Amazing! I always thought that 8.1 was the one people hated. I'd like to see this engine in a GMT400 model.
a lot of people favor the LS for parts availability and weight savings, but the big block still has a small following
Yeah people hate them cause you can't throw a bigger turbo on them and dump a bunch of black smoke out the back like a Duramax or a Cummins. They might have more fans if they were optional in half tons, but gas big block heavy duty trucks, that really hasn't been a popular thing since the 80's/early 90's, the Dodge Cummins pretty much changed the world 30 years ago away from gas engines in heavy duty pickups.
I'd love to put an 8.1 in my 96 Buick Roadmaster sedan. The LT1 does okay, but it really needs a lot more. I only get 12-16 MPG anyway, so I might as well have a bigger engine
you should!
Just doing an 8.1 swap pulled the 5.3 used the wiring from the 8.1 and ecm getting a fuel pump relay that's clicking turns over but won't start. Should I go with the 5.3 harness and ecm. What did you do to do drive by wire as my 5.3 was drive by cable.
I stumbled across a company called Raylar Engineering in my research of this very same swap for my 03 Silverado that actually makes what appears to be good parts for these 8.1 Vortecs, forged stroker cranks and aluminum cnc ported heads could make that a whole lot more fun
Yeah, I’ve seen a ton of their parts and hope to get some when I build the engine
4.30 with a big block😳 throw a 3.42 or 3.23 in it and watch that big block torque come alive.
you'll have to check out one of my latest videos, we did just that
Hello lt need a bit of your expertise on my 2007 Yukon it has an la engine keeps reading low pressure oil even after I changed the oil pressure sending unit , have u have any good advice on this thk you sir
theres a chance the gauge is reading correctly, and you do have low oil pressure. supposedly the o-ring that goes between the pickup tube and the oil pump can shrink over time and cause low oil pressure. If it were me, I'd make sure to remedy and low oil pressure issues asap because the engine is at stake.
I can tell you from experience that truck would be more fun and feel faster with a much higher rear gear. As in 3.08s or 3.55s. With 3.08s it would feel like a rocket ship on the highway and still have plenty out of the hole on street tires. Very low gears in a truck like that would only be useful if pulling a heavy load like a large camper or towing a race car. Low gears are also great for smaller high reving engines
I had a 2001 Sierra with the 6.0L V8 and 4L80e/4L85e. Was a stout truck and then the 6.0 wanted to blow. Had plans to swap a built 8.1L and a built Allison 6 speed but ended up having to lose the truck. Currently got a 94 F-150 that I plan to swap a BBF V8 and have an adapter housing made for the Ally 1000 with the SAE 2 or 3 bellhousing. I'm choosing a built Allison because why the heck not... The C4/C6 and TKO crap is SO OLD......So here's what I got in mind.
-Built, Stroked and Sleeved 460/7.5 (stroked to 501/8.2)
-MSD Direct Ignition
-Jon Kaase HEMI heads
-Built Allison 1000 6-Speed
-Stand Alone TCM (Hoping I can set my shift points to 6400)
-Sterling/Dana axle conversion
-4.10 Gears
sounds like a fun build! I have heard the allison has trouble shifting at higher RPM, but no firsthand experience with that.
@@LawrenceTolman If the idea with the Allison goes wrong, I may be able to contact Performance Automatic OR Browell Bellhousings to see if they can make a bellhousing to fit on a chopped Ford 6R80 trans. I don't wanna give up on the 6-Speed auto conversion since I'd like to have a double overdrive on an old engine.
You won;t need to go to that high of an RPM with the Allison. I have a 8.1/Allison and the gear ratios are perfect. Just find the right rear end gear so as the transmission shifts through the gears it stays in the power band. On an 8.1 it's like 3600rpm, my 8300lb truck moves right out from a stop all the way up to 85(I don;t take it past that, it's a stock 2500HD not a race car)
There really is no comparison to older transmissions or even the 4L80's, the Allison is a game changer and you can alter your entire build around it. It's like having a T56 that shifts itself, the ratios are just spaced right and are all pretty close.
Saw the title and hit subscribe. That’s awesome man
Let’s say you had a stock stall, 4l80e with say 3.13 gears or so for a daily driver 8.1 swap. Think that would get ok economy? Like at least 12 city 16 highway if you didn’t romp it? Always wanted a big block half ton
it might get a little better mileage, but with a 4l80 and those gears, it would be a dog out of the hole, and you'd be putting your foot into it a lot just to get moving (which uses a little more fuel).
Subscribed LT! NOW LET'S SEE SOME TWINSIES IN THAT BAD BOY! ALWAYS WONDERED ABOUT THESE BBC ENGINES AND CAN'T WAIT TO SEE WHAT YOU DO NEXT!
thanks for the sub! working on turbo stuff this week, should have an upload soon
So I got a 2005 8.1 and it has the Allison as stock.. but can I put a transmission from a 6.0 2500 of the same year? Or what's the best economical way to go I just need the truck to work and daily drive everything else is perfect
you have a blown Allison transmission? You can surely swap from an Allison to a 4L80e, it will just take some creative wiring and some adjustments in the computer.
@@LawrenceTolman no it's just acting up on 2nd gear they hold the first and it jumps to the Third...
@@LawrenceTolman what are only after I R and it turned it off and turned it back on if I turn it on let it warm up and drive it the whole vehicle drives perfect..
That 8.1L Vortec in that Silverado is a beast LT.
thanks! its a blast to drive
@@LawrenceTolman You're welcome LT. Are you planning on adding aluminum heads to the 8.1L Vortec as well.
Its hard to find a 2500 with the 8.1 these days. it only shows me 22 trucks on autotrader (with 4wd selected). So next best thing would be getting a 2500 with a 6.0 and swapping it to an 8.1. However, I notice that it is also difficult to find a 8.1 engine and tranny combo for sale on ebay (or any other website)... Sucks, im graduating soon and will be getting employed right off the bat and would like to finally upgrade to a better truck. Always wanted an 8.1...
I have an old carburated 460 big block out of an 80's E-350 RV I want to stuff into my ugly 2002 F150 once I kill off the bone stock 4.6 modular that's currently in it. After the engine swap I want to cage and back half it. I'm going the prerunner route rather than a street truck. I wanna be able to hit a curb doing 80mph and keep going! =^D
I need about 10k to 15k worth of long travel suspension components though, and a few years to build it. I'm getting the engine for free off my step brother though, so thats a very good start to this crazy project of mine.
Hopefully you figure out what’s making those rear tires wear like that. Keep us updated 😂😂😂
I hope so too!
@@LawrenceTolman Check your tire clearance, I’ve seen a tire Spaghetti like that it was because the tire was rubbing against the wheel well when accelerating/or carrying to much weight.
Judging from this video I could take a pretty good guess.
I had a 02 Avalanche 2500 4x4 with the 8.1l it was 373 geared and I had folks with 6.0 and 6.2 trucks ask me what in the hell do you have under that hood we cant keep up!...so yes the 8.1l is a total different ball game!..mabe a game changer!
Best looking truck for its year
Question please, was the Helwig rear swaybar worth installing? I have a 2010 Chevy Silverado 4x4 (all stock suspension) and was wondering if this swaybar would be beneficial for towing and hauling. Any info would be helpful and thank you in advance!
Imagine a T56 behind it! Now that’d be fun
It would be
For sure;)
Been looking for one of the Suburbans with these in good shape.
Subscribed and following this build.
thanks!
I’m sure you know this but if you’re gonna turbo it, you can definitely reuse your stock bottom end, just add ring gap. Especially if that engine has like 100k plus miles of daily driving, everything’s happy and working together (rods, pistons, crank, etc) and can take quite a bit of punishment. For instance the 5.0 sbf I’m swapping into a ranger, the stock gt40p pistons and rotating assembly will take more power than the block will as long as the rings are gapped properly (shooting for 500 to the tire with a mild ish buildup and turbo) so I’m sure your 496 can take some lickin
im on the fence about it honestly (opening up the gap). I know its a good idea, but mainly because I do plan on building the engine to hold 1,000+ within the next year it would be 2x the work for a temporary short term solution... but we'll see what happens
@@LawrenceTolman well if you're going all out and have the budget, of course go with forged. But I know of a ton of stock bottom end engines holding ridiculous amounts of boost with just ring gap. A buddy of mine had a 351w from an 89 f250 with twins on 24 lbs making over 1000 on the stock bottom end and it held for a long time. Wasn't even the pistons that gave up in the end. Main bearing grabbed the crank at 6500rpm and thats all she wrote. Those junkyard motors can surprise ya lol
LT would be interesting to measure before and after with a loaded trailer between mile markers measured distance.
that would be cool
How restrictive is the manifold? Can the 8.1 flow air up top or is it choked up? Also are there any camshafts available? If so i would do that first
the intake is a little restrictive, and there are some mods you can do inside to remove them. and yes, there are plenty of cams available. it would be fun to do a NA build first for sure
A budget pump gas upgrade for most of your towing duties. Makes sense to me.
This a damn good video. I subscribed. Keep up the great work!
thanks!
What do the maintenance numbers look on that 8.1? Like gaskets, lifters, alternator all that good stuff.
I know the parts are available and affordable, just like with the 5.3, and these 8.1s are very reliable from what other viewers have commented
Well, I hope my 5.3L never needs replacing, but if it does, this confirmed my decision to drop an 8.1L in. My worries then are the 4L60E and G80 diff in the rear😆
it would do a number on the stock trans for sure
Will the computer from any LS such as the 4.8, 5.3 and 6.0 run the 8.1 or did you have to swap the ECU or reprogram?
yes, any LS computer and wiring harness will work, but the wiring needs to be modified slightly (check out my wiring video). I did the first start up with the 5.3 tune, but I did flash in an 8.1 calibration afterwards
How does a 2000 chevy 1500 have front springs?
you mean coil springs? the GMT800 1/2 ton trucks which were 2wd all used coil springs, the 4x4s used torsion bars
I'm looking at a truck today that's a 93 3 + 3 long bed 4x4 nice truck but it came with a 350 anything I can do to make it so it can tow something??
As good or better then powerblock tv!! I'm used to hearing you speak I love it
I watched your lowered 4x4 Silverado video. Do you know any lowering kits for 96 k1500 4x4 suburban.
the front would be the same as the K1500, the rear might depend on if there's any crossmembers or anything that would be in the way of going too low... but you should be able to use the same flip kit as for a silverado. Just don't know if the axle has enough room to go that low
@@LawrenceTolman alright thanks for the info
You said the 2005 rotors/calipers bolt up without any adapters, right?
yup, as long as you also have the 2005+ caliper bracket
@@LawrenceTolman Thanks! About to do the control arms, rack/pinion, and 2/4 drop as well.
What transmission you think i can use on my 1997 silverado C1500 with the 5.7 to try to upgrade just a little bit i love the truck but is can a slow....
unless you plan on putting in a lot more power the 4L60 is the way to go for simplicity sake, and has a better gear spread than the 4L80. But, if you want to make a lot more power the stronger 4L80 might be a swap to consider
@@LawrenceTolman thanks for the info love the videos keep it coming 👍
@@eduardogutierrez665 trucks are slow, they are not meant to be sports cars
My 4.8L gets 14-15 mpg how is the 8.1L getting the same
Hey where are you filming? I noticed the license plate is Maury county TN where i used to live but the landscape looks more like the four corners than middle TN. Any love the channel.
thats a keen eye... I did move a couple miles to the west and haven't re-tagged the trucks yet. UT actually.
@@LawrenceTolman Man that is quite a move. You get tired of the Nashville traffic too? LOL
Shout out from Arizona 😎 keep up the good work. Just subscribed.
Awesome! Thank you!
Awesome video bud! I've got one I'm putting in an '81 c10. Any ideas about motor mounts? Matching the th350 trans as of right now.
the 8.1 has a dual motor mount pattern on the block, so it will bolt directly onto your SBC motor mounts
So the gist of it, no replacement for displacement
in my book, yes. and also, a more unique package once done
A roots style supercharger can wake up a small v8
Idk but I have 5.3 2018 Silverado but it burns tire at a stop like if I was holding the break.. makes a lot of smoke from that pull
I love how you tell me what I need ti know without getting into friendship zone... that comes later
It's a good bang for the buck truck. I'm closer to $5K on my swap, but I changed the transmission, had to source brackets for the Squarebody swap, and did headers and a segment swap on the PCM for the 4l80e. But....Big Block! For comparison, you cannot get into an 8.1 2500HD even with 200k+ miles for under $12k, and....Big Block.
Why go with the 4.30 gears?
Respect no doubt bad ass built we are here in this car and truck game to do orginal things go fast have fun and love what we do if your gonna whine about fuel mileage then your in the wrong game when your building hotrods fuel means nothing and if you can't afford the gas then you shouldn't be building hotrods power is what its about and originally and fun I love what you did here keep up the good work man damn rite
thanks! its a fun truck to drive, regardless of the fuel lol... and tires
For the money I would turbo the 5.3. But big blocks have a cool factor that can't be matched. One more thing. You blow up the 8.1 those aren't super easy to find. 5.3 on the other hand are everywhere for cheap. Stock 5.3 with a decent turbo setup then just swap in another 750 motor when she goes.
you are correct on all counts, and thats why I'm gonna be super careful with the 8.1 before I build the bottom end
Would that 8.1 go in my 03 2500hd easy? I want to go bigger. What’s mpg? 😅
Iv got a stock 05 gmc sierra with a 5.3 and has 20 inch gmc wheels from a newer truck. My truck roasts the tires just fine and honestly from flat footing it does it better and has a better smoke show. Not sure what 5.3 you have lol.
Love the look of the truck tho. I'd like to lower my truck since its a 2wd about like yours.
sounds like a badass truck!
I have a 1998 k2500 5.7L w/4L80e I want more power and I want to swap to the 8.1 vortec what all do I need and is it difficult to swap
I did a 5.3 to 6.0 with h/c/I in my 1500 silverado. I haven't gotten it dynoed so I cant say what power it makes. But after seeing your videos, if I could do it again I'd 8.1 swap it, dont get my wrong. The 6.0 is great and fun but 496 is just so much cooler. And I can tell you I have wayyyy more then $3000 total into everything in my truck so the 8.1 swap seems to be alot better of a budget build. Not to mention depending on your area or what kind of deal you can find changes the price. My 6.0 in the same situation as your 8.1 was only $1350