Hey, The super 44 is a great muffler but lacks a little low end power you'll see from say magnaflow, borla or gibson. I had flowmasters on my last truck and the sound is unriveled but there's not much of a change in throttle response. I'm pretty sure the pipes are 2.5" wide, which if you just wanted to replace the muffler and tip is fine. The benifit of going dual exhaust with 3" Pipes and 3 1/2" Tips you'll get a much deeper more aggresive sound no matter what brand you choose. As far as high flow cats are concerned, Magnaflow makes some universals you can pick up at summitracing.com for about 65 bucks each. I added a Hypertech Max Energy Programmer to my 07 and love it. Huge gain in throttle response and almost 3 mpg gain. Let me know if you have any more questions and let me know how that 63 series works out as I'm mostly likely going to be getting one pretty soon. :great: