Hey Gearheads,
I have a 85 IROC stock 305TPI. I am swapping an L98 and 700R4 from an 89 Formula. Looking for the basics. I know that I need to get a new chip. Its coming with the TPI (22 lb injectors). Any words of wisdom from those who have walked this path ?
Thanks:hail:

 

Something to consider: I think the '85 TPI is a mutant that parts are only used on '85 engines. In '86 they changed the computer and I think the harness is different too. Is the 89 engine a MAF or Speed Density system? I forget which year they made the change to SD. I would use the computer and the harness from the 89, if you have it. I don't know if you can even get a 350 chip for the '85 computer. I'm not sure if they use the same chips as the '86 and newer, but something in the back of my mind tells me they are different. The first year of the 350 TPI was '87. Other than the computer/harness, it should drop right in. Does your '85 also have the 700-R4? If not, then you might need a different trans mount or even crossmember. Good luck.

 

You will need to use the exhaust manifolds from the 89 (the centerbolt valve cover will make contact with the non centerbolt manifolds). You could always just drop in a set of headers. You will need to use the intake manifold base from the 89 along with the runners and plenum from the 85. You can either get 22 lb injectors, 24 lb injectors and decrease fuel pressure a bit, or use stock injectors and raise the fuel pressure 5 psi. I've heard conflicting reports as far as the need to change the knock sensor, but since it was easy, I changed it.

The computer should let the car run ok, but the car will run better with a custom program. Unfortunately I'm not familiar with anyone who programs the 85 computer. The 87 car uses the faster computer and the cold start valve so I would consider changing to that ECM / harness.

My car also ran warm with the factory single fan, so I swapped in the dual fan setup from the factory 350 TPI cars.

Good luck!

 

I am using new SLP 1 3/4 headers. The motor is complete with another TPI (22lb). It has the stock computer so I am hoping that it will plug into my current wiring harness.
Anybody know if that is fact or fiction ?

 

I think you can repin your harness or use it as is, but in any case, follow this link:

http://www.eecis.udel.edu/~davis/z28/ecm_swap/

You'll find what you need there.