Hey, Ive got a 94 gs and ive got a greddy exaust off a 1990 ls will it work with my gs?

 

No, it won't bolt on at all. If you have a Greddy SP or something for a 1990 teg, it should have a muffler that runs perpendicular to the piping, correct? Now, a 1994 muffler runs parallel to the piping. I have seen people fit a 94 style muffler onto a 1990, but never the other way around - of course, anything is possible if you wanted to weld on new hangers and fabricate some new piping for the 1990 exhaust but it wouldn't be worth it in my opinion.