I am building a 350 tpi for my 85 iroc that used to be a 305 tpi. I have all of the lower end done but my question is can i use a wiring harness, ecm, tpi from an 86 vette in the camaro or would the harness just be a pain to make fit?

 

If your car was originally a 305 TPI, then use the harness that is in the car already, all the wiring is the same between the 5.0 and 5.7 TPI. As far as controls go, the only thing you should have to change for the 5.7 to work is the knock sensor (get one for an '87 IROC 5.7 TPI). As far as physically fitting in the car, the only things that should need to be changed are the oil pan and oil pump, and the exhaust manifolds. If you have the Corvette accessory system/brackets, they should be changed over to the ones that came off the 5.0 so everything goes together correctly, as I think the Corvettes had a different serpentine setup.

 

First, welcome aboard thirdgen.org.

The bad news is the '85 TPI ECM wasn't their best effort. But, I believe you can use the Camaro harness with the Vette ECM. BUT, I don't know that for a fact, so you might want to dig up the pin-outs for each and verify that.