Vortec 454 7.4l vs Vortec 496 8.1l

Gilderbeast · Sep 8, 2019

I've narrowed down my choices for my next build. I am trying to decide what would be the better of the two.

The 7.4l out of 96-00 GMT 400 platform puts out 290 hp at 4000 rpm and 410 ft-lbs at 3200 rpm. The 8.1l out of 2001-2007 GMT800 trucks/suburbans/vans puts out 325 hp at 4200 rpm and 447 ft-lbs at 3200 rpm.

So obviously the 8.1l makes more power but has very little aftermarket support (raylar) and you will pay outrageous money for more power and are pretty much limited to exhaust, intake, and a tune. Thats why I'm looking into the vortec 454 as well. More cylinder head choices, cam choices, aftermarket efi, headers fit better, coil near plugs kits available, and if I really wanted I could do forged rotating assembly much cheaper than the 8.1.
Thoughts?

Arkansas_V8 · Sep 8, 2019

If you intend to modify, then 454.

I want a 8.1, it will suit my Suburban just fine, loud exhaust, and a tune are all I need.

1979k10 · Sep 8, 2019

I would go 454 since you're looking at aftermarket supply. Once you warmed it over a bit the factory specs won't matter.

78C10BigTen · Sep 8, 2019

Arkansas_V8 said:
If you intend to modify, then 454.

I want a 8.1, it will suit my Suburban just fine, loud exhaust, and a tune are all I need.

I know a guy that has one... hooked to an allison

Arkansas_V8 · Sep 8, 2019

78C10BigTen said:
I know a guy that has one... hooked to an allison

I am just gonna stay with my th400.

78C10BigTen · Sep 8, 2019

Arkansas_V8 said:
I am just gonna stay with my th400.

If i did anything trans related id go balls out and swap to nv4500

bucket · Sep 8, 2019

The vortec 7.4 cylinder heads are supposed to be pretty decent. Keep me in mind if you end up with an unused set

Craig 85 · Sep 8, 2019

I've had a (4) 454 trucks/Suburbans. 2 carbed & 2 TBI. I've had (2) 8.1's. 1 with a 5 sp Allision, 1 with a 4 sp auto. All where mostly stock. The 8.1 with the Allision had a chip and aftermarket cold air set up. I liked the 8.1 more than the 454 in all aspects. You barely noticed when I had my 30 ft travel trailer on it. I agree aftermarket is pretty limited though even when they were new.

Jrgunn5150 · Sep 8, 2019

If you really want to get into head swapping and all that, like, legitimately spend 3 or 4k and build a 5, 600 hp N/A engine, the 454 is a better base.

If you just want to tow your junk on cheap gas, the 8.1 all day. You don't need Raylar at all to make nearly 600 ft/lbs of torque. They routinely exceed 500 with just a exhaust and a tune.

The reason there's no aftermarket is there's no need for an aftermarket. I can tow my C10 behind my Silverado with a loaded truckbed camper on the back, uphill, with the converter locked, on 87 octane gas.

If you don't want to really build something, the 8.1 is already mostly done.

If you're fine with dumping a few k into something for performance, do the 454.

TerryRH · Sep 8, 2019

I vote 8.1 with exhaust and tune. You can open up the heads for a little more if you want, and they even have more cam choices.

Shorty81 · Sep 9, 2019

Could go old school 496. Stroked, bored, carbed 454. Makes loads of low end torque.

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TerryRH · Sep 9, 2019

.....

Richard Schultz · Sep 9, 2019

The price for the two are about the same go with the 8.1l

TubeTruck · Sep 11, 2019

I was having the same debate with myself and decided to also go with a 7400. Support goes way back and if it breaks I would think it's easier to get parts for. Keeping it stock for a while with the multi efi, then I plan on building it, stroke it, cam it, probably aluminum heads and putting it in front of a 4L80E and an NP205.

shiftpro · Sep 11, 2019

TubeTruck said:
I was having the same debate with myself and decided to also go with a 7400. Support goes way back and if it breaks I would think it's easier to get parts for. Keeping it stock for a while with the multi efi, then I plan on building it, stroke it, cam it, probably aluminum heads and putting it in front of a 4L80E and an NP205.

That's the combo, and twin stick the 205 while you're at it.

Vortec 454 7.4l vs Vortec 496 8.1l

Gilderbeast

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Arkansas_V8

Proud Redneck

1979k10

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78C10BigTen

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Arkansas_V8

Proud Redneck

78C10BigTen

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bucket

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Craig 85

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Jrgunn5150

Questionable methods

TerryRH

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Shorty81

Baby Boomer

TerryRH

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Richard Schultz

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TubeTruck

I'm from Boston. Deal with it.

shiftpro

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