brightred6

I plan on keeping the single exhaust for the mustang (better performance), I will add Long tube headers soon...heres the question
Is the stock exhaust pipe big enough or should I increase the size all the way back? it will be N/A if that helps.

stags

First off, dual exhausts see performance advantage over single exhausts. Thats just how life is.

BUT you will not see a huge difference with an NA setup and the stock system works well with NA applications. Most will tell you that long tubes are a waste and sound terrible without cats