Sorry if this has been answered already, I haven't been able to find out for sure though. I know the stock inlet for a GT exhaust is 2 1/4 inches, but is this the same for the GTP? I plan on getting rid of the stock muffler and putting in a Y splitter, running into two magnaflow glasspack mufflers and 4 inch tips. Possibly replacing the stock resonator with a glasspack too. Has anyone used glasspacks as mufflers before and possibly have parts numbers? Or suggestions?