The_Mexican, I love the sound of my Magnaflow cat-back. It has a deep tone at idle and is fairly quiet till you get on it except for the standard drone at 1800rpm. With the stock exhaust and SC on my truck it had a whoooshing sound at above 4000rpm, kinda sounded like a jet taking off, but now just a deep tone. I didn't notice any improvement in performance. I am not sure if it flows enough for a SC application but I believe it is a good compromise to get the sleeper look. If I had it to do over I would probably have a custom exhaust made up with dual 3" pipes from the cats to a single 4" pipe, then to a Magnaflow diesel muffer, then out to a 4" tip in the stock location.