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.
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’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 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.
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 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.
@@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..
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 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. 👍
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.
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!!!!!
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 !
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😆
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!
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.
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 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
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
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 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
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
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.
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" :(
@@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’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
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...
@@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.
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
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 hate being myself but, a 370 shortblock, with stock 5.3 706/862 heads, elgin 228/230 or 238/242 cam, PAC1218s, ebay long tubes, TBSS intake, ebay 102 TB, thinner cometic headgaskets in the 0.041"-0.027" range to up compression, 160 tstat, NGK TR6s and a Circle D or Yank 2800-3600 converter would rape that thing all day long on HP and I believe that it would also beat it on TQ. Depending on the cost of the 0.030" over 6L it could be cheaper, the same or onky slightly more than this 8.1 swap. The biggest question is how much boost can an 8.1 take? A gen IV 6L shortblock with gapped rings has made 1,500+hp for Richard Holdner maxing out a 3 bar map sensor and not breaking. Cool build, subbed, very interesting.
there's no question a 6.0 could make a lot of power with a good cam and some other mods, but honestly, this build wasn't/isn't about doing what everyone else has done. I want to try something out of the ordinary... Oh, and yeah, the stock 8.1 wont hold up a lot (if you believe the internet) so it will eventually get built and probably stroked out as well.
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).
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!
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.
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.
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!
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.
please make a video comparing 7.4 v8 with 8.1 v8 their power differences and technical improvements! thank you I'm a fan of your channel and I love v8 I hope one day I can put one of these on my silverado here in Brazil.😎
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
Be a good swap for my C30. The original TBI 454 is getting tired. Wish the accessory brackets were easier to find (for a squarebody you need the Workhorse brackets that put the A/C compressor up top)
Thinking about taking my 472 out of my 1970 Cadillac Deville convertible and doing the 8.1. Was considering a 6.0 or 6.2 but I think I would prefer the 8.1.
@@LawrenceTolman the 472 actually runs damn good. Just want a turn key car. I’m guessing a 4L60 or 80 could go behind it. Don’t know what mods will have to be made to the rear end, drive shaft, etc.
Very cool, I love a sleeper. Did you know the Colorado SS single cab weighed only 3500?? You could put a stock ls7 in that and smoke a 2023 Camaro. I'm down for a muscle truck 💪
I think it's worth it it a unique build that most people can't say they have every one fan boys over the 5.3 and don't get me wrong it's an excellent engine but it's better to stand out in a world full of all the same
The cool factor is there, but the 5.3 with heads/cam puts you in the same tq range, runs cheaper, bolts in, weighs less, better mpg, easier to find parts, etc.... If you can make 750whp with the big block, please do a budget break down with a parts list, because thats where most people fail.
i like the idea of a turbo. it's funny you sound like me talking about my 6.0 only mine isn't doing donuts. aint tryin' either. it's got locker, 4:10 gears and better tires. high traction, similar alleged power, though not the torque and original parts.. something would prolly break. it'll turn them over though usually the wife aint thrilled if i do lol. i have got her sideways out of lights a couple times. it's also in a 3/4 ton 4wd frame. it did give a newer challenger r/t a run for it's money with all that weight. amazing engines.. i say that being a ford guy my whole life. just knew the ls was a really good one, got lucky on a deal with my brother inlaw and bought it.
I had a K2500 HD with an 8.1L mated to a 5 speed Allison. At best, I was able to achieve 11 mpg on the highway. I thought the power and torque was impressive until my dad proved his stock Duramax equipped truck would accelerate much faster and he was towing a 7500 pound camp trailer. That being said, get that turbo on your truck LT.
My Yukon already has an 8.1, it would take an engine swap if I even wanted to put a small block in it. The only downsides of the 8.1 are 10mpg and they burn a lot of oil
The real question is can the boosted 5.3 do it on 87 octane. The cost of 91 octane fuel for the rest of it's life is the big answer to me. Thank you big block.
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.
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
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! 👍😎
> 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
You are the Richard Holdener of truck building. Keep up the good work!
well thank you! those are some big shoes to fill...
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.
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.
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
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
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.
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 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.
Smiles per gallon out of that 8.1 and thats what matters. Can't wait for the next phase.
plenty of smiles driving 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
I’d love to have off road truck with an 8.1 and Allison.
bulletproof combination
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
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
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 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. 👍
Also love that you ran the numbers and said what you paid. Love it!! Thanks for this series
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
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 can’t wait for more vids on this build!
making some more as we speak
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!
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
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 is a great swap. Thanks for the info and detailing the minor issues with it. Great channel
Thanks for watching!
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
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
I am absolutely in love with the 8.1
they are such a fun engine
And not to forget: worthy acoustics, finally 😉
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.
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?
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
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
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
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 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
A budget pump gas upgrade for most of your towing duties. Makes sense to me.
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!
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.
Like your videos, but your 14 to 15 mpg estimate seems optimistic, particularly with the gearing
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
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’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
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
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...
Also I have 4x4, crew cab, steel flat bed, full front end replacement. 8100 lbs empty.
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 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've been really interested in this swap thanks you've opened my eyes so much
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.
4.30 gear with an 8.1 is not smart. Why didn’t you put a 3300 rpm stall tc in there too?
How’s that? Most big block trucks with the 4l80 (the trans I have) come stock with 4.10s, so 4.30 is very close to that.
@@LawrenceTolman Those trucks are heavier, have taller tires and they are design to tow 10k+ pounds.
I hate being myself but, a 370 shortblock, with stock 5.3 706/862 heads, elgin 228/230 or 238/242 cam, PAC1218s, ebay long tubes, TBSS intake, ebay 102 TB, thinner cometic headgaskets in the 0.041"-0.027" range to up compression, 160 tstat, NGK TR6s and a Circle D or Yank 2800-3600 converter would rape that thing all day long on HP and I believe that it would also beat it on TQ. Depending on the cost of the 0.030" over 6L it could be cheaper, the same or onky slightly more than this 8.1 swap. The biggest question is how much boost can an 8.1 take? A gen IV 6L shortblock with gapped rings has made 1,500+hp for Richard Holdner maxing out a 3 bar map sensor and not breaking. Cool build, subbed, very interesting.
there's no question a 6.0 could make a lot of power with a good cam and some other mods, but honestly, this build wasn't/isn't about doing what everyone else has done. I want to try something out of the ordinary... Oh, and yeah, the stock 8.1 wont hold up a lot (if you believe the internet) so it will eventually get built and probably stroked out as well.
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).
Been looking for one of the Suburbans with these in good shape.
Subscribed and following this build.
thanks!
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!
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.
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
That looks so much better! Keep the paint!
I have almost zero paint and body skills so thats the plan haha
ive built the same truck, just working out the wiring bugs, cost me a lot more because i built the engine and swapped in a bigger trans.
theyre a lot of fun!
Best looking truck for its year
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.
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
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.
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.
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
This a damn good video. I subscribed. Keep up the great work!
thanks!
I love how you tell me what I need ti know without getting into friendship zone... that comes later
please make a video comparing 7.4 v8 with 8.1 v8 their power differences and technical improvements! thank you I'm a fan of your channel and I love v8 I hope one day I can put one of these on my silverado here in Brazil.😎
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
As good or better then powerblock tv!! I'm used to hearing you speak I love it
Shout out from Arizona 😎 keep up the good work. Just subscribed.
Awesome! Thank you!
Be a good swap for my C30. The original TBI 454 is getting tired. Wish the accessory brackets were easier to find (for a squarebody you need the Workhorse brackets that put the A/C compressor up top)
yeah, they will be harder to come by. I saw someone on a FB group for 8.1 has brackets they make for the swap I think...
Thinking about taking my 472 out of my 1970 Cadillac Deville convertible and doing the 8.1. Was considering a 6.0 or 6.2 but I think I would prefer the 8.1.
that would be awesome! oil pan might be a bit of a chore, but I say go for it
@@LawrenceTolman the 472 actually runs damn good. Just want a turn key car. I’m guessing a 4L60 or 80 could go behind it. Don’t know what mods will have to be made to the rear end, drive shaft, etc.
Imagine a T56 behind it! Now that’d be fun
It would be
For sure;)
LT would be interesting to measure before and after with a loaded trailer between mile markers measured distance.
that would be cool
11 mpg I own one, power is great
Very cool, I love a sleeper. Did you know the Colorado SS single cab weighed only 3500?? You could put a stock ls7 in that and smoke a 2023 Camaro. I'm down for a muscle truck 💪
Those late model Z71 wheels look great with the red brake calipers.
I think it's worth it it a unique build that most people can't say they have every one fan boys over the 5.3 and don't get me wrong it's an excellent engine but it's better to stand out in a world full of all the same
Gen 6 Big Block is closer to 4.8-6.0 in layout than previous gens.
lots of similarities in the design
My 4.8L gets 14-15 mpg how is the 8.1L getting the same
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?
Why go with the 4.30 gears?
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
The cool factor is there, but the 5.3 with heads/cam puts you in the same tq range, runs cheaper, bolts in, weighs less, better mpg, easier to find parts, etc.... If you can make 750whp with the big block, please do a budget break down with a parts list, because thats where most people fail.
I plan on doing a budget and parts overview for each stage of the build, so stay tuned for the info!
Fantastic sir.
i like the idea of a turbo. it's funny you sound like me talking about my 6.0 only mine isn't doing donuts. aint tryin' either. it's got locker, 4:10 gears and better tires. high traction, similar alleged power, though not the torque and original parts.. something would prolly break. it'll turn them over though usually the wife aint thrilled if i do lol. i have got her sideways out of lights a couple times. it's also in a 3/4 ton 4wd frame. it did give a newer challenger r/t a run for it's money with all that weight. amazing engines.. i say that being a ford guy my whole life. just knew the ls was a really good one, got lucky on a deal with my brother inlaw and bought it.
the 6.0s are great engines, and the HD drivetrain is nearly bulletproof... nice trucks
I had a K2500 HD with an 8.1L mated to a 5 speed Allison. At best, I was able to achieve 11 mpg on the highway. I thought the power and torque was impressive until my dad proved his stock Duramax equipped truck would accelerate much faster and he was towing a 7500 pound camp trailer. That being said, get that turbo on your truck LT.
yeah, I've got the L5P to handle the towing duties and it is impressive for sure
Hey LT I just subbed up wit ya. Glad yo see you got your own thang my guy. Good to see you brother!!! Much Respect
thanks for the sub!
My Yukon already has an 8.1, it would take an engine swap if I even wanted to put a small block in it. The only downsides of the 8.1 are 10mpg and they burn a lot of oil
Replace valve guides/seals
havent driven mine enough to find out how much oil it burns. but it does burn a lot of rubber haha
Lawrence LT Tolman my Yukon is also really heavy so that probably doesn’t help the gas mileage or oil burning problem
The real question is can the boosted 5.3 do it on 87 octane. The cost of 91 octane fuel for the rest of it's life is the big answer to me. Thank you big block.
very good point
All in the tune
One of my favorite gm truck body styles. Sounds pretty good too. I bet you like wearing those rear tires out. ;)
I am! although now I gotta buy some new ones lol
Inspiring build for sure. I'm planning a budget build on my 99 expedition 4.6 v8. Rated at ~230hp/300tq from factory, goal is ~350hp/360tq.
Are you planning to do 350 whp NA? I think that might be pretty difficult for that engine I'm not too sure tho
@@grumpyolddan no lol, crank hp. 350whp would be extremely expensive and not worth it imo haha. Might as well go coyote at that point.
It's an awesome truck LT the old saying there is no replacement for displacement holds true cubes are king.
Agreed!
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