The mac cat-back systems sound really good. If you want killer sound I have heard that the MAC "flowpath" dumped kits sound amazing. I've been contemplating that as my next set-up. Its a toss up between that and the SPINTECH Pro streets-also very aggressive sounding exhaust. Do a search for the thread that explodinggopher made a while back, it has all sound clips and vids of exhaust systems, different cams, s/c, and other misc stuff. Great thread and may help point you in a direction for your exhaust set-up. Good luck in either way you go.