As of right now I have the factory dual cats on there. I just bought a set of SLP 1 3/4 headers from a member on here. The y pipe that came with the headers is for single cat.
My three options:
1. Buy a high flow cat and mate the SLP's up to the single cat
2. Buy the dual cat y pipe from SLP and buy two high flow cats
3. Dont buy either, have the exhaust shop that is welding the y pipe build a custom y pipe dual cat y pipe and buy two high flow cats.


My goal for this car is an 11 second time slip.... id be happy with 11.99x

 

Hey man, what made ya change your mind about the slps? I know you sold off that one set you ran. I would stay with a single cat system. Will flow equally as well as a dual cat system + less weight, less cost, more room under the car for sfcs or whatever. How has my old 10 bolt lasted for you?

 

I needed a new rear end and you had the 10 bolt for sale. I wasnt thinking performance when I traded the SLP headers for the rear end...I was thinking of getting the car to the track. Besides, these headers look better . I didnt even run the set that I sold/traded with you. I had bought those off of 91greenbird, the guy in MD.
The bolt has lasted, but I only ran the car 4 times since your rear end. Didnt notice any acceleration difference from the 9 bolt 277 to the 10 bolt 323 from you. I have 373's ready to put in, but dont know if they would be worth the $500 shops want to charge me to install them.

 

Have an exhaust shop make you up a 2.5" dual cat y-pipe with mandrel bends. Its the best way to go. 4 cylinders flowing thru 2.5" is better than 8 cylinders flowing thru 3". The SLP y-pipe and the factory y-pipe are 2.25".

 

For what it is worth most if not all of the y-pipes for either set up are on clearance on thier website. If that helps you out any.