[XelginX]

ok, heres the deal. i have a 1990 5.0 vert. that i baught from my bro. as far as i know it was bone stock when i got it. but ive notice on other peoples stangs w/ stock exhaust there are 4 cats on the h pipe mine only has 2 and ive ive always heard that the tail pipes stock are only 2 1/4 (mine from the mufflers back are 2 1/2. but the h pipe is only 2 1/4) did some cars come with better flowing exhaust than others? if any one can help me out i would appreciate it.
thanks

[DJorgie76]

I have never heard of that. Was your brother the original owner? If not it is very possible that the previous owner to your brother changed it. Exhaust is probably the most common thing that mustang owners change.

[Fast1]

are you aeeing the 2 right after the headers?