Im having a hard time decided which car to lsx swap and would like some input. Its between my '88 C4 (L98/4+3). Car is pretty clean and Ive had close to a decade. I love the car and how well it handles. The other car is my '89 Firebird (vortec 350/t5) that Ive been working on for the past year. Its not the prettiest car but I have put a good bit of work into. What do you guys think??

 

The Firebird will be much, much easier. You really only need adapter plates for the motor mounts, and a different crossmember, a fuel regulator, and a few wires spliced for the ecm and everything else will bolt right in. Most of the hoses, lines, and electronics will work just fine. With the thirdgen, a ton of stock LS1 4th gen will just "bolt right in" like the entire fuel tank and fuel system, torque arm, rear end, driveshaft, front engine accessories (except AC), stock manifolds, etc. And don't forget, you can literally buy the entire "swap kit" from hawks if you want. They make "LS swap" everything for these.

The C4 from what I've read is a PITA. You have to cut up the Kmember for the front accessories (not just the AC, I could be wrong here), modify the firewall, make an adapter for the unique torque arm, probably custom hoses for things like PS, AC, and coolant.

 

See bold for answer.

It sounds like the C4 is your babe and the favorite. If that's the case let the firebird wait it's turn.

 

I would also say the Firebird for ease, but C4 if you want a ton of stuff to work though. I read a thread on LS1tech or corvetteforums with an LS C4 swap. it was a LOT of work in the tunnel to get the T56 in, unless you keep the 4+3, or go to a 700R/4L60, but I would dump that 4+3, lol. Not very strong and I don't think parts are easy to get