I have a setup close to that. I have 2 - 2.5 hi flo cats going into a Dynomax muffler - dual 2.5' in and a single 3" out. I then ran 1 - 2.5 pipe straight out. All I will say is you've got to like it LOUD!!!!!!! At 1st it sounded a bit ricey, but after a month or so the sound changed for the better. It almost sounds like a V8 now. Oh ya. There's a bit of a drone you have to get used to when your running about 120kph on the Highway.