H or X pipe ?
 

Hey ya'll,

Will the 2.5" "H" or "X" pipe fit into the stock cat back 2.25" pipes? If not what do you need to do, replace the cat back? What about the stock headers?

Thanks

Stock V8 exhaust pipes are 2.5" I believe. Thats from the header to the tailpipes. You shouldn't have any problems with fit or flow going with aftermarket exhaust parts whether it's just the replacement of the stock H pipe or headers or the cat-back. For the best bang for the buck, replace the stock H pipe that has 3 cats per side and go with X pipes. The 99+ GT's have only 4 cats compared to our 6.

No, they are indeed 2 1/4", but it still will bolt up fine.