oo i see. the orp will make it noticably louder. and replacing the mufflers on the factory exhaust can also sound very good depending what you use.
i would say straight pipe the middle muffler (IIRC that's the bigger one) and put a cherry bomb or what ever you wanna call it on the front one. then alot of people cut the resonator off the back and use a flex pipe with chrome tip.
there are many ways to change the tone, you find something nice that works to you!