WARNING - LONG POST!
My AOL crapped out on me so I'll respond to your email here.
I'll tell you everything I know but I'm sure there's more. I'd suggest contacting Ed Parks as well. He is always more than willing to provide information.
What's been listed is pretty much the most of it. You'll need to locate a Fiero V6 engine and obtain these parts:
- lower intake
- secondary intakes
- plenum
- valve covers
- air filter housing and tube
- ECM and wiring harness
- flywheel (if you have the complete engine, you've already got this but I don't know if the 3.4 flywheel works - ask Ed or others here)
Some folks have said the cradle for the V6 is different that the I4. Others have said this is not true. The cradle in my car now is NOT the cradle that was in the car when I took it to Ed. Whether or not (a) he simply grabbed another cradle and began assembling without having to wait on my car or (b) the cradle is from a V6 car - I don't know.
The 4-banger cars came from the factory with a single-core radiator. The V6 cars use a double-core. For my swap, Ed kept the single-core radiator. His argument was that the single-core radiators, though having a smaller capacity, have a quicker flow. So, with the SC radiator, you're cooling less coolant but you're cooling it faster. Anyway, he said he's done many 3.4s like this and has never had a problem. The more people you ask about this, the more opinions you'll get. Again, talk to Ed for more information (and probably a better explanation too).
The A/C compressor on the 4 cylinder cars cycles differently than on the V6 cars. Both versions use the same compressor, just different settings. Ed said he changes these settings.
The 4-banger cars and the '85 GT all had reflector-style gauges from the factory. The '86-'88 V6 cars got backlit-style gauges. The 4-banger tach will not work with the V6 engine. So, if you intend to keep your reflector-style gauges, you need to "borrow" the tach from an '85 GT. For my conversion, I had Ed install a set of backlit-style gauges from an '87 GT. Also, keep in mind (THANK YOU, DREW!) that the 4-cylinder tach contained an oil pressure gauge ('85-'88 only, '84 had a voltmeter). If you convert to the backlit-style, you will lose this VALUABLE gauge (this gauge is located in the auxiliary gauges that sit above the radio pod for the backlit-style). For my conversion, I had a set of auxiliary gauges installed.
The fuel pump from a 4 will not flow enough gas to satisfy the thirstier 6. You'll need to drop the tank and swap the pumps.
The V6 hooks up to the coolant system differently than the I4. Unless I'm mistaken, everything behind the pipes that run underneath the car has to be changed.
Exhaust is not an issue unless you want it to be. Most will agree that the Fiero dual-exhaust is more for looks and sound than it is for flow. For my conversion, I kept my 4-banger's single-outlet system. In fact, Ed used everything from my car's system from the cat back. To go dual-outlet, I would have had to convert to a GT rear clip. Easily done, and not too expensive, but it wouldn't have looked right with my car's "non-ground effects" body style. Going to a Formula rear clip would have been better but Ed says the GT's trumpets rub against the Formula rear clip's narrower openings and damages them. Using different tips solves that problem but I was reaching the end of my budget so decided to wait. Besides, my car is a sleeper - from the outside, it still looks like a 4-banger. It just doesn't sound like one! :-) Having an '88, you've already got the Formula rear fascia (all '88 coupes had the dual-outlet clip). So, you've got a few more options available.
I'm sure there's more stuff - and if I think of it, I'll post it here.
Good luck and hope this helps.
