i currently have stock exhaust manifolds into a catco 3" cat into a 2 1/2" pipe back to a flowmaster muffler with dual 2 1/2" outs. purchased the car that way.

car currently has a 305. i'm going to mess with it a bit before i swap it out for a 400. i don't want to have to do the exhaust twice, so the system i have in mind is probably more than i need for the 305. will probably actually hurt low end power a bit on the 305.

i have a set of slp 1 3/4" dual-cat headers. i'm getting ready to test fit them and do any necessary dimpling (hopefully i won't have to) before i send them off to jet hot.

the "y" pipe isn't actually a "y" pipe. it has two 2 1/4" tubes to go to the cats, but nothing afterwards. i guess it's my responsibility to have that done.

i plan on going with two random technology cats. since the 2 1/4" and 2 1/2" cats are the same price, i'm thinking i'll go with the 2 1/2" cats to minimize any restriction from them, then have a "y" made after the cats from two 2 1/2" pipes into a single 3" pipe. even though the pipes into the cats are only 2 1/4", i'm thinking going 2 1/2" into the "y" would make it flow a little better.

from the "y", i plan on going 3" back to the muffler, then two 2 1/2" tailpipes out.

i'm getting a little burned out on that "flowmaster sound". is there another stock replacement, single 3" in, two 2 1/2" out muffler that flows as well as the flowmaster but sounds different?

 

c'mon guys ... nobody?

 

Dynomax muffler http://store.summitracing.com/partde...rt=WLK%2D17536

RT says their p/n for dual cats is 802200 (2 required). Their install kit is 516002. I assume you have to use original factory dual-cat parts to make it work, but I don't know from personal experience. Since the cat bodies are the same size, the size of the inlet/outlet isn't going to make any difference since the pipes determine the flow restriction.

A cat-back made for dual cats wouldn't require any fabrication.

 

wouldent u be able to use a borla exhaust ?? im getting my SLPs by next month to put in my lil iroc but i dunno if i should keep my flowmaster exhaust or go wit something else.