350 to 454 engine swap?

Mr Construction · November 5, 2006

I've been looking for an early 90's chev (2500 or single wheel 3500) that has an ext cab, 4x4, long bed and the 454. All I've been finding though are a lot of trucks with 350's So I am wondering if i can just do a simple engine swap to a 454?

Rob

Mr. Construction

Tucson_02Silverado · November 5, 2006

1500???

worst case you might have to drill new holes for the engine mounts and the transmission crossmember.

After all there was the 454SS in a 1500 SCSB so there is a factory example to go off of.

2500/3500 had the 454 as an option so the mount points should already be available in the frame

Mr Construction · November 5, 2006

To clarify I am looking at the k2500 (3/4) for the engine swap. As I see it everything but the engine and cooling system should be the same. I may have to change the motor mounts and put in a bigger radiatior, but and correct me if I'm wrong the rest of the drivetrain should be the same?

Thanks for the reply Tuscon

Mr. Construction

95Sierra2500 · November 5, 2006

Probably need new motor mounts, possibly a larger radiator (but maybe not, depending on your GVW), and almost definately a different bellhousing/trans, since IIRC the 454 and the 350 do NOT have the same bellhousing pattern, and I don't know if those years saw the removable bellhousings on automatics.

Tucson_02Silverado · November 5, 2006

The 454 does generate quite a bit more heat than the 350, I'd play it safe and go for the big radiator....when summer comes around you'll be glad you did.

The Turbo400/4L80 trans is longer than the 700R4/4L60, so the crossmember mount location as well as the front/rear drive shafts from the transfer case changes. There is a "short" TH-400 but it is shorter than the 700R4. Not to mention the spline count changes between them all. But I'm assuming you're using auto trans.

1 engine mounts

2. trans crossmember

3. drive shafts, rear pinion angle

4. radiator, shroud, mounts

5. donor computer and accessory brackets for the 454

6. rebuild the TBI (pre 96??) with 454 injectors

Have you thought about getting a GM Performance HT383 crate? other than beefing up the auto trans, and for insurance a bigger radiator, computer programming, vortec manifold (96+), it's plug and play as far as mounting goes. 400ft/lbs 2500-4000RPM

There's a few articles if search the Net on the 350 to HT383 swap. The HT383 has been out for a few years now so there's gotta be a lot of conversions out there. GM Performance Parts sells the HT383E as an emissions legal 96-99 swap, but it's a short block of the HT383 and in the long run cost a lot of money for the "legal" sticker and cam as opposed to just swapping the carb intake on HT383 with a vortec intake.

Mr Construction · November 6, 2006

Thanks for all the info, sounds like the engine swap would be fairly simple. This would be a daily driver and tow rig. I own a construction company so it would definitely get a work out. It would be used to move a 36' tri-axle tool trailer and my flat bed trailer (mostly backhoes and tractors). Maybe I should swap in the 8.1 instead? How hard would that be?

Rob

Mr. Construction

95Sierra2500 · November 6, 2006

Thanks for all the info, sounds like the engine swap would be fairly simple. This would be a daily driver and tow rig. I own a construction company so it would definitely get a work out. It would be used to move a 36' tri-axle tool trailer and my flat bed trailer (mostly backhoes and tractors). Maybe I should swap in the 8.1 instead? How hard would that be?

Rob

Mr. Construction

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I doubt you'd need more than a 454. If you do, then simply rebuild it with mods before you install (cam, head work, headers, etc. etc.). Hell you can even buy ported throttle bodies for a 454.

My dad's '94 with a 454 pulls his 42' fifth wheel with no problems, and he's also used to to move tractors and whatnot for his friends.