First post on TGO(wooWOO), did some looking around and didnt see any information on swapping out a i4 to a v8. From what i've seen/read i assume it's the same as going from v6 to v8. here's the scenario;

Was given a 85 firbird i4/speed by my buddies uncle, drove it home and it brought back memories of my 87 Trans-am. Body is nearly perfect(besides the hideous bumpers). Interior is rough but complete.

Got to snooping around and found a 88 Trans-am GTA 305TPI/5speed that had been wrecked, but the motor/trans were good. The interior is also not perfect but i can salvage enough between the two and the local junkyards to make a whole int. lol.

I plan using the entire drive train, suspension, and rear end from the GTA, dropping it all into the firebird(including the bumpers/ground fx) and leaving it fuel injected. Will i run into any issues or should i have pretty much all the parts i need at my disposal? Any headaches or problems i should know about before i jump into this mess?

 

You are doing it the best way possible. I did the same thing with an 85 4 cylinder and an 86 Trans AM.

If I were you, I'd ditch the entire 4 popper wiring harness, I mean the whole car harness, every bit of it. I had the biggest problems with the 85 out of any third gen that I've done. The dash was the horrible one with only lights and no gauges, the tail lights were the 82-84 style, and on and on. I used the entire harness from the 86 and it went great. Like you, I was also upgrading from firebird to T/A, and because it was an 86 I had that goofy third brake light on the window. I stripped the 85 down to the shell (I mean EVERYTHING) and then rebuilt it with the Trans Am stuff. It came out pretty well, I think. I made a little money and had a lot of fun along the way.

Make sure you change all of the fuel lines as well, THEY ARE ALL WRONG FOR TPI!!!

 

Did you also swap over the body piece from the trans am? do you know if the fenders on a firebird are the same as the ones on a transam?