I'm picking up the GMP touring exhaust and extruded honed manifold. The only thing I'm missing is an aftermarket downpipe and cat. Does anybody know where I can find one that is similar in size to the GMP exhaust, with a metal matrix cat, and not produce too much more noise?

 

I personally would stay away from those parts! If your gonna spend the money, i would honestly reccomend getting the cat back magnaflow system. I ordered a downpipe with hi flow cat from cobalt addiction. It is called XTC dwnp,andhi flow cat.Both will cost you about 800 or so, and you will add yourself an xtra12-18 hp. Headers you would want would be stnls steel(ceramic coated) to keep heat in, since gm cars get extremely hot. Good Luck!