It'll help the flow 'supposedly' giving you better top end. It will hurt your bottom end to a degree because it will remove that much more back-pressure.

I don't see much of a need for a high-flow cat on your setup, but that's just me. I researched them before I went ahead and just found a used OEM cat to put on my setup. I didn't see much of a need for one for the price. :dunno: