I have a 44 series Flowmaster 2 1/4 in dual 2 out on a 2.6 with a weber and a pacesetter header on Geronimo and it sounds fine for me - but the cab has dynamat and foil/foam insulation so the noise level is better than a non insulated truck. The pacesetter is about to be changed out for a new Doug Thorley header , the same design as the one camoit has, after 22-24 years, its about rusted through.