You want the camaro/firebird (F-body) muffler with the inlet and outlet on one end, and another outlet on the other end. Buy the 2.25" inlet outlet muffler, and have your exhuast shop flare the inlet to 2.5" (the passages inside are already 2.5"+). This keeps you from having to neck down BOTH outlets to your tips.

i liked the flowmasters 80 series but how hard is it to put in

Hey wren kinda but are you gonna post new runs from the G-Tech Pro anytime soon? I wouldn't mind seeing what your car does..