V6 to V8 swap thread

Fjtgonefishing said:

this is probably the dumbest thing you've ever heard of but here goes. So I have a Ford van sitting in my garage and I got this dumb idea of swapping out my 3.4sfi v6 for a 5.4l triton v8. So now I'm trying to figure out if I'm gonna have to swap the transmission in my firebird or it if it'll work in the new engine, if not what would I need to make it work?

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Your profile info indicates your V6 has a "6 speed manual". Since the T56 was not available with the V6, appears you have already done a transmission transplant. If that is correct, do you have the LT1 version of the T 56, or the LS1 version? McLeod makes a universal, modular, explosion-proof bell housing that connects the LS1 version to virtually any engine.

On the other hand, if your V6 actually has a T5 5-speed manual, which is the only manual available with the V6, it's most likely too weak to stand up to a truck engine that produced torque rather than HP. You would be looking at a Tremec TKO 500 that could stand up to the torque. Those are available for Ford engines.

Personally, based on 150,000 miles on a Ford F-150 with the Triton engine (company supplied truck), it has issues of its own, the major problem being the spark plugs with the ridiculously long nose required to reach through the bulky head. Typically, the nose breaks off when you try to unscrew the plug since the annulus between the head and the plug nose is packed with compressed carbon. That engine is also very wide, due to the OH cam heads. Simply measuring the width of the Triton engine should enable you to determine if it would even fit in the F-Body's narrow engine bay.

Easiest swap would be a Gen 1 small block Chevy (SBC). They put that engine in the 3rd Gen Firebirds and Camaros. That would mate well with a 700R4 4-speed overdrive automatic trans, again, what GM put in the 3rd Gens. Do you want to stay with a fuel injected engine (recommended) or use a carburetor? The L98 350ci (5.7L) V8 engine was used in the later 3rd Gens and has excellent low end torque, but runs out of steam above 4,500 RPM. That can be solved with a set of cast iron Vortec heads from a late model pickup, and a matching intake. The L98 has a bit too much torque for the Tremec 5-speed T5 manual that was used in the 3rd and 4th Gens, GM wouldn't even offer the L98 with a manual trans. However.... best of both worlds - a T56 6-speed manual from a 4th Gen V8. Adapter kit required.

Alternatives include the Gen 2 SBC LT1 350ci (5,7L) V8 engine that was used in the 4th Gens from 93-97. Torque almost at good as the L98, and another 1,000 RPM if heavy breathing. T56 bolts right up with no adapters. But, the LT1 has issues with the Optispark distributor, which GM conveniently located under the weep holes for the water pump. But.... you can easily make up to 500HP at the flywheel, normally aspirated. And the block is good for in excess of 1,000 HP at the flywheel with nitrous, turbo(s) or a supercharger.

Another alternative would an engine from the LSx series.... known as the Gen 3 SBC (but totally different in most aspects). Introduced in the Corvette in 1997, and in the Firebird/Camaro in 1998. Virtually unlimited HP, dependent only on your wallet or the credit limit on your cards.

Inherent to the installation of any fuel injected engine is the matching wiring harness and ECM/PCM. Interfacing the later model harnesses to your body connectors becomes a bit of a challenge. Again, sticking with the L98 solves the harness mismatches.