I just straight piped my Duramax ... and I hate it. It has a terrible drone at about 1500rpm and again at about 2200rpm. Now I am almost forced to replace the exhaust. I am looking for something quiet inside the cab (NO drone) that will lower the EGT a bit. I dont hot-rod, but I do tow a 5th wheel and will be making a trip to the Rockies this fall. And ... Im not made of money so the more economical the better. Please give me some suggestions and vendors and web sites.