If you're going to invest in a HFC, you might want to spend the extra bucks for a muffler shop to replace your 2.5" flange with a 3" flange and 3" pipe. Then you won't have any bottle necks in your exhaust. That's what I did.

For high flow in a cat and max HP, consider the Mil-Spec unit. I love it on my X. No stink unlike a test pipe.