stop playing around and go with a magnaflow- it is a perforated through pipe design that doesn't restrict flow one bit, or even slow it down- which is important on a rig running a catalytic converter, so long as the muffler is right behind the cat.... it's all about convection and keeping that little conveyer of exhaust pulses moving along..

borla is a good second choice. similar design.. stay away from chambered designs with these engines.

 

You got a high flow or stock cat? My truck got much louder when I removed the stock cat for a magnaflow direct fit (stupid clogged stock one).

 

Stock cat that was the cheapest I could find.

I found that when I replaced my cat, the exhaust actually got a tad mellower at idle, but louder at higher RPM.