ls1 into 89 v6 firebird - Third Generation F-Body Message Boards

s346k · 11-28-2008, 04:39 PM

i have been wanting to swap an lsx into a 3rd gen pontiac for awhile. i helped a friend of mine (board member randy87iroc) a little bit on his 3rd gen ls1/t56 swap, so i get the gist of things. sans a natural disaster, i will purchase an 89 v6 firebird roller next week, i looked at it today. now i have a couple questions regarding the suspension and rearend.

will the stock v6 springs work? i've searched; some say the car will sit low, others say it will sit high...so which is it? i have a set of stock 02 z28 springs in my garage - will they work on the 3rd gen car if neede?

will i need a special trans crossmember to work with a th350 and stock torque arm?

being that the car was a v6 (automagic), i assume it has an open dif rear with most likely a 308 or numerically lower gear ratio. this will not work for me. it will be ok to get bugs out of it, but when i get serious it will have to come out. will i be able to swap a 4th gen 10 bolt rear under the car without hassle? i want disc brakes and a posi. i plan on buying different wheels because of the offset.

any help is appreciated, thank you.

five7kid · 11-28-2008, 06:07 PM

You can't use a stock trans crossmember with a TH350.

'89 V6's had 3.42 gears. You can use a 4th gen rear, but it's an inch wider on each side, so you need more offset than 3rd gen wheels. 4th gen wheels fit fine.

I hope to be able to tell you shortly if the V6 springs work. But, they should.