hey, i want to do an ls1 swap, and want to know which long tubes fit best in a 3rd gen? i want to run an auto tranny if that makes any difference. thanx

 

Nobody makes headers for an LS1 swap into our cars. You must use either the stock LS1 manifolds or fabricate the headers yourself.

 

JBA makes a set but they are garbage and only make like 3 hp more than the stock ones. Custom ones are the way to go or you can have a set of stock manifolds extrude honed a bit. No thirdgen header will fit a gen III motor.

 

I'm wondering if anyone has really tried using any full length or long tube headers though? I better some of them would work, maybe with a little modification. As for shorties on a LS1, they're not worth it... just get the '01-'02 factory manifolds... they're as good as aftermarket shorties.

 

well, i know none are made to fit directly, but i was wondering the same. i bet some of them will fit. like i said, i had hooker long tubes from the lt1 in mt lt1 3rd gen fro previous years. i'm convinced on those slp long tubes, but I love stepped headers.

 

From what I've read about the stock LS1 manifolds, they are actually very good. They are not nearly as restrictive as a typical SBC manifold is. I would just run the stock manifolds. You won't lose much power by running them, and a set of custom made headers are scary-expensive.

 

Has anyone tried the mac intermediate length LS1 headers on a 3rd gen?