I have the same 2.5' Brullen cat-backsystem as you, and I put a sho-shop Y-pipe w/ no cat on. I like it except for the rasp. When warmed up it sounds good, LOUD. Now I want to do the Mystery Mod, and then put on a High Flow resonator to kill the rasp. Wonder how it would sound. Any way Ive heard some bad stuff on Peformance Fords Y-pipe here on the forums, I'd get the sho-shop and then before you put it on have it Jet Coated to prevent heating up of your oil pan. This is my only concern with this y-pipe.
1998.5 Silver SVT
Brullen Cat back
kkm intake
sho-shop Y
Aussie pipe
Pcv seporator
5% mirror
painted calipers