originalsin

ok my buddy is willing to bend up a pipe for me, full catback, for free. but what i need to decide is this, i can go either 2.5 or 3inch, currently im not boosting, but come spring i will be, so my question is will 2.5 be ok if im only going to run low boost(7-8psi on pretty much stock ls) im prolly going to use an excellorator muffler from his shop, oem look but straight through design. i want to keep it low pro, because cops around here are d*cks and write tickets for that kinda stuff, i alrdy have a burnt orange paintjob to draw attention(not my choice in color, i bought it like that and it was a deal) so anyways im just looking for opinions, and how much would running a glass pack also hurt my performace, i really dont want it to be loud, like i was thinking 3inch with glass pack and the muffler, then when i go turbo, i coudl get a highflow cat and possibly ditch the glass pack, lol anything will be better the the straight side pipe im running now rofl