SoDakStang

(Assuming you are running basically a stock car...) Running a different cam should have little to no affect on the cats. The only thing that should affect it is if you are dumping a ton of gas into them to the point that they basically ment down inside. If all you have is a visual test and are concerned with the cats, hollow them out. Just run a pipe through the middle and put whatever cam you feel you want in there. Problem solved.