Originally Posted by Phimosis

If you reall want to approach it that way, try it with the cats first, dyno it, look at your boost, then put the stock cats back on, dyno it and look at boost again. You'll find that with the cats, you make more hp with less boost. Put the more restrictive cats on and boost pressure goes up, but make less hp. Correct me if I'm wrong, but more power at less psi boost is better/safer.