what is the difference if i just got a flowmasters 80 series crossfow muffler 2.5". compared to getting a full catback system. is the increase of power really that greater

i have a 94 camaro 3.4l ported TB k&N CAI

 

don't even waste your money on a muffler, just get a cut-out and that way you can a lot of noise when you want it and cap it whne you don't.