This is kindof a cross-topic thing because it has to do with custom exhaust manifolds. for 3rdgen. It also pertains to the motor swap so i posted in both locations


I am currently doing an LS-1 swap and was wondering about headers as well. I am aware of the differences between the L98 and the LS1, but I am unsure of the dementions of the exhaust exits and bolt pattern. I am wondering..

L98 header flange
o oo o
1 23 4

LS1 Header flange
o o o o
1 2 3 4


L98 header on L98 flangeflange
o oo o
|| |||| ||
1 23 4

L98 headers adapted to LS1 flange
o o o o
|| \\// ||
1 23 4
/|\
|
note the center 2 tubes are modified

Pardon the crude interperatation.

wondering if the distance between holes 1 and 4 are the same on both the L98 and the LS1.. would it not work then to just change the header flange from an L98 flange to an LS1 flange (for bolt holes) and then modify the set of L98 headers to go into the LS1 flange?

if it were that simple it could be done from just about any exhaust shop if given the proper dimensions.

hopeuflly this can be done, I was hoping to adapt a set of hooker 2055's to an LS1 in this manner.

EDIT: spacing was all messed up on it. couldnt fix it but I think you get the picture.

 

umm to save you time, you could do one of several things...
1: Use the existing manifolds... .they flow pretty good till your around 375hp. Maybe a set of Z06 manifolds would work?
2: Using manifolds, make a header flange and then adapt the tubes to that.
3: Find someone who has already done this! Im sure third gen resourse would give you plenty of info on what they did, though i think they did use the existing manifolds and custom bent exhaust from there.