I know some of you have gave your input....but

I want to replace the headers, H-pipe (I hear to an X pipe), cats, exhaust with the best money can buy.....I figure if I am doing this, I want to use the best....do any of you have Dyno results to back up your experience? Should I replace the cats? or is it not worth it to replace the cats? I like a really deep throaty sound....that sounds like it should be coming from a vette.....while I am doing this...should I do the headers at the same time? With the same company as exhaust? or does it matter?...mixing and matching headers with cats and exhaust? Please help me.....I am looking for the best HEADERS, H PIPE, CATS, EXHAUST combination I can find. Thanks for your help.

First, I think you should run cats on the street - its the law and even if you can get away without . . .

There are super-size cats out there. If you buy headers from Koch's they will sell you a set prewelded on. They make about 8 - 1-0 HP difference.

On an otherwise stock vette C5 or C6, long-tube headers alone, with new large size tock exhaust, will add about 20 HP and about 20 ft lb torque, with more than that much torque low. If you have the PCM reprogrammed you will probably pick up another 7 HP. A good cat-back will add only a little bit. These are the results I got on my stock 02 ZO6 with headers as the first addition, and also results on a 98 Camaro with the LS1 engine.