stick with a 4" system from the turbo back. I have a 4" 409 stainless steel MBRP on my truck , fits very good and would buy there kit again . Without a cat its not going to be loud in the cab but outside on the sidewalk they make some noise if your just standing there. Nothing to harsh but just as a heads up every system with a 4" or 5" strait threw muffler is going to bark some.... None of the aftermarket systems are as quiet as stock. Cold air kit , save your money! not much power to be had and a drop in filter into the OEM airbox with a few new holes added to your OEM air box will make with in a few HP of a 300 dollar kit
93 c-2500 6.5td,96 6.5td x cab,01 GMC lb7 Xcab ,2004 lly crew cab ,2006 lbz crew cab,honda CBR1100xx,2003 polaris prox 700 , 2001 31' holiday rambler 10K lbs house on wheels!