i had a Piper back box on my AX GT, they are insane! really loud!
although it does your nut in after a while, personally i would get a scorpion full system if it is for road use & a supsersprint manifold (4-2-1)
P.s. Piper eshausts fit like SH*T! the hangers are sooo weak they break after a few hard corners!