Why does it say for performance exhaust only? It is made for the GMPP system which is 2.25 inches. Seeing as how the stock system is also 2.25, why would it not work on that? I just want to get a flowmaster for better sound and get the bigger tip to fill in that huge gap.

 

im sure its just some fitment issues, or a sceme to get people to buy the exhaust as well, instead of just buying the tip.