8.1 swap in a 1500?

tmoreau · February 9, 2004

I doubt I would do this, but there is a tempting offer on a 8.1 from a wrecked truck on the table. Is it feasible to swap an 8.1 into my barebones 4000lb 2wd 1/2 ton? Its a reg cab short bed v6 with a 5spd, I know the nv3500 wouldnt be up to snuff but I would think the rear axle could stay (3.08 gear, should be pretty good ratio). I would be able to pull what I need from the donor truck (all wiring etc) but would probably need new front coil springs.

Anyway, just wanted to see what you guys thought about the idea, it would be sweet to have that engine in my little truck!

The SPEEDY · February 9, 2004

The first problem I see is the motor mounts. There was a truck that had something similar to this done, but they took a 2500 hd frame and cut 2 feet off of it and put a 1500 bed and cab on it.

It would be pretty sweet. It really depends on how much you can afford to spend.

tmf6902 · February 10, 2004

I think there is a size issue with it fitting????

tmf6902 · February 10, 2004

OOPS...double post......mods please delete me!!!!!!!!!!!!!!!!!!!

tmoreau · February 10, 2004

I think there is a size issue with it fitting????

I wouldnt think so, the truck is the same size from a 1500 v6 thru a 3500 duramax under the hood.

GRUMPYK3500 · February 10, 2004

I would think some H.D. parts would also be needed . Like rear axle ,transmission ,steering, springs. ect. also note you will need the HD hood.

John

Wingnut · February 10, 2004

Plus the entire BCM, PCM, and pretty much the entire wiring harness.

I don't know if the frame would take the torque when you went to pull something either.

.02

GMC_DUDE · February 10, 2004

Many years ago I test drove something similar. It was a 1960 Buick which the owner had replaced the original engine (331 CID I think) with a 455CID monster. Going in a straight line that thing would move . HOWEVER, the first curve I came to nearly scared me to death!! You see, he never upgraded the suspension and the whole front end pitched and swayed like a rowboat in a hurricane . I suddenly realized why he was selling it so cheap. Needless to say, there was no deal. Something to keep in mind when pondering the swap.

GMC_DUDE

americanmuscleman · February 18, 2004

You'd be better off dropping one of the LS1 style engines in (5.3, 6.0, 5.7 LS1, 5.7 LS6) than a 496. The 496 is a heavy motor (cast iron block and heads). An LS1 or LS6 would be a much easier swap (and nearly a direct swap into a truck with a 4.8, 5.3, or 6.0L). LS1 derived engines have an aluminum block and heads, and are a much better match to a 1/2 ton truck. The 4.3L V6 probably weighs more than an LS1 (4.3's have an iron block and heads), so your front suspension would be ok. You could run a 4L60E or T56. Drop a lumpier cam in an LS1 with some headers, an intake system, and tuning, and you'd have a quick truck. With some ported heads and a real aggressive cam you could have a solid 450-500hp motor.

99-2door · February 20, 2004

You'd be better off dropping one of the LS1 style engines in (5.3, 6.0, 5.7 LS1, 5.7 LS6) than a 496. The 496 is a heavy motor (cast iron block and heads). An LS1 or LS6 would be a much easier swap (and nearly a direct swap into a truck with a 4.8, 5.3, or 6.0L). LS1 derived engines have an aluminum block and heads, and are a much better match to a 1/2 ton truck. The 4.3L V6 probably weighs more than an LS1 (4.3's have an iron block and heads), so your front suspension would be ok. You could run a 4L60E or T56. Drop a lumpier cam in an LS1 with some headers, an intake system, and tuning, and you'd have a quick truck. With some ported heads and a real aggressive cam you could have a solid 450-500hp motor.

Nope!

None of the LS1 derived engines have aluminum blocks except for the LS1 (5.7L) itself. The 4.8L and 5.3L have cast blocks with aluminum heads. Some 6.0L even have cast heads.

The motor will fit under a stock non-HD hood (Suburbans and Avalanche don't have HD hoods, neither did GMC HD trucks with the 8.1L. In fact if you look at an HD hood it has little to no extra clearance.), and the motor will mount anywhere a small-block will.

That would be one hella cool truck, I would love to do that swap. At the bare minimum you would need to install front springs from a Big block truck (C2500)

Cool Zr2 · February 20, 2004

NO kidding, put a vette engine in the truck, you will get awesome power with awesome gas mileage, that 8.1 is a pig and gets horrible ges mileage.

americanmuscleman · March 25, 2004

You'd be better off dropping one of the LS1 style engines in (5.3, 6.0, 5.7 LS1, 5.7 LS6) than a 496. The 496 is a heavy motor (cast iron block and heads). An LS1 or LS6 would be a much easier swap (and nearly a direct swap into a truck with a 4.8, 5.3, or 6.0L). LS1 derived engines have an aluminum block and heads, and are a much better match to a 1/2 ton truck. The 4.3L V6 probably weighs more than an LS1 (4.3's have an iron block and heads), so your front suspension would be ok. You could run a 4L60E or T56. Drop a lumpier cam in an LS1 with some headers, an intake system, and tuning, and you'd have a quick truck. With some ported heads and a real aggressive cam you could have a solid 450-500hp motor.

Nope!

None of the LS1 derived engines have aluminum blocks except for the LS1 (5.7L) itself. The 4.8L and 5.3L have cast blocks with aluminum heads. Some 6.0L even have cast heads.

The motor will fit under a stock non-HD hood (Suburbans and Avalanche don't have HD hoods, neither did GMC HD trucks with the 8.1L. In fact if you look at an HD hood it has little to no extra clearance.), and the motor will mount anywhere a small-block will.

That would be one hella cool truck, I would love to do that swap. At the bare minimum you would need to install front springs from a Big block truck (C2500)

Good catch 99 2-door! I accidentally wrote LS1 derived engines have an aluminum block and heads. LS1 and LS6 engines only have the aluminum block and heads. LS1 derived engines have a cast block with alum. heads.

All 6.0's have aluminum heads. They use the same heads on 4.8's, 5.3's, and 6.0's.

Sweet truck 99 2dr!

michigan2500hd · March 29, 2004

Nope, not all 6.0's have alum. heads my 99 came with iron

heads from factory.

juicy · April 4, 2004

how much does an 8100 cost?

americanmuscleman · April 4, 2004

Nope, not all 6.0's have alum. heads my 99 came with iron
heads from factory.

Man, you guys got me twice in this thread!!

I didn't realize the 99-00 LQ4 6.0L had cast iron heads. I knew the newer LQ4/LQ9 had aluminum heads, so I just assumed the older ones did too. I have never heard or seen a 6.0L with the iron heads. I stand corrected!