your pipe is the same as theSC's. the midpipe is 2.25", and it spits to 2" going into the mufflers. If you have a stock engine, true duals realy arent neccesary. I had my car on a dyno with my flowmasters and no 3rd cat, and my current 2.25" duals. I made 8 rwhp with the duals, but lost 14lb ft over the 2.5" flowmaster single. My recomentdation is a single 3" pipe and no 3rd cat. You can split it into duals out the back, or just run one 3" pipe all the way out the back, make people think its a V6...for a second or two.
"Keep making it thinner until it breaks, then go one size bigger."
My Cougar XR7