OK, I've read all of the articles on exhaust. I'm looking to get a full exhaust system (headers, cat, cat-back) by Christmas. I was planning on getting some Comptech 4-2-1 s/s mig welded headers, carsound cat, and GReddy EVO cat back. My whp goal is about 190whp-200whp. The GReddy EVO is 60mm piping, the right size for my goal. I want 60mm piping all the way through the exhaust (headers to muffler) right? If this is so, what are some headers that have 60mm piping? Does Carsound only have 2.25" and 2.5" cats, or do they have 60mm cats as well? If I am completely wrong in my assumptions, tell me what I should be looking for. Sorry about all the questions, I just want to make sure that I buy the right exhaust for my car. Thanks!