Yes you read the title right. I plan on swapping a TPI 305 from a 86 Trans Am into my 85 Iroc which also has a 305 TPI engine. My question is about the wiring harnesses. Is there any difference between the Chevy and the Pontiac harness? Should the PCM be the as well?

 

I tried to swap a 305tbi from a 1988 firebird to a 1987tpi injection iroc car. I used all the accesories from the original iroc motor so all the wires fell into place. BUT. the accesories from the firebird and the iroc where reversed. Meaning that the alternator and A/C compressor where on different sides. I forgot which was on which side. But yes there was a difference in the harness for the alternator and A/C compressor. there was also a difference for the sensors on the engine block itself. It wound up being easier to strip the firebird block down and then put the iroc block next to it and transfer all the componets over. good luck.