I have a 1985 IROC that was originally a 305 TPI automatic trans converted to 5spd std. The car was factory loaded with Air, cruise, power everything. I got it from my friend who pulled out all TPI wiring and converted it to carb. He changed fuel lines, and fuel pickup but left the body wiring intact. The dash and all interior/exterior lights, as well as the power windows/locks/hatch, and wipers work just fine. He gave away all the TPI parts years ago so I have to start from scratch.

When he swapped to carb be built a 350 non-roller with vortec heads, xe274 flat tappet cam, and performer RPM air gap intake w/750 edelbrock carb. Engine dyno'd at 386 hp. I want to swap back to TPI with a 350 even if it means not making as much power.

I picked up a 1991 Trans AM GTA with a 350 TPI automatic trans that is mechanically and electrically sound that I want to use for the parts swap.

I will have no problem with 95% of the swap. I have all the wiring diagrams for both cars and have built and installed a few engines. My questions are:

1. Will I be able to adapt the 85 HVAC controls to activate the air conditioning?
2. The original 1985 air conditioning equipment was ripped out and lines cut going to the evaporator. Will all 1991 components fit right into place?
3. Will I be able to adapt the warning lights from the 1991 harness and dash into the 1985 dash?
4. Do I need to worry about the VATS if using the 1985 ignition?
5. Will I be able to connect the cruise control to the 1985 cruise lever?


As far as I can tell the EFI harness and dash harness are pretty much 2 separate pieces. Right now with the car converted to carb with a coil on cap HEI distributor and the EFI wiring ripped out, everything still works as it should.

I know the wiring in late 80s early 90s camaros/firebirds is slightly different than the early to mid 80s. Will I run into an incompatibility issues that shouldn't be to hard to correct?

The new engine combo will be a 350 with the vortec heads, edelbrock vortec TPI lower, AS&M Siamese extrude honed runners, ported plenum, and either the XE274 flat tappet cam or something different. maybe a ZZ9 cam or something that peaks a bit lower? Not sure, any suggestions?

Some picks of the 1991 Trans AM I'm using for parts. Picked it up for practically nothing because of the body condition and that the guy thought it was a 305.

 

Those beautiful tail lights! Lol. Read over the wiring very carefully. A good amount of difference. Component wiring changes and such. The battery wiring may be on opposite sides. I do believe the dash wiring to be same connectors tho. Read austinthirdgen.com I believe. A wealth of wiring diagrams.

 

I've been over to Austinthirdgen.com and had a look through the wiring schematics.

Not really much going on in the TPI sub-forum here. Thought there would be some people here to chime in, I guess not. Should I try another sub-forum?