That's whats Rush said as long as I have the cat I'm good. And if I lose it I can always change the baffle down the line

 

OP here, I got the 2.5" baffles. At cruising speed the sound is perfect but when taking off hard not as loud as I would like. I would think with the cat and 3" would be just about right. I will say it now sounds like a Harley and it's much better then stock slip on's.