You are not going to get any significant HP gains from punching the cats. BTW, there are 4 cats on the SRT. If you really want to get some serious HP, you need to get the following mods:

1. New CAI - The stock CAI is too restrictive.
2. Add either a supercharger pulley, or a crank pulley.
3. Get a custom tune for the ECU.

There is plenty of information on these mods in the forum. Just do a search on each of these, and you will learn everything that you need to know.

Good luck with your mods.

Oh, and welcome to the forum. Lots of great people and information in here.