This kit will convert your single exhaust system to a dual exhaust system with a Performance muffler and dual tail pipes. For Chevrolet Silverado / GMC Sierra 1500HD and 2500HD (GAS ONLY) 2001-2006 applications. All Wheel Bases. Most jobs take 1 afternoon and basic hand tools . 2 and 3 piece tail pipes make for easy installation. Please note : This system is designed to replace your factory OEM exhaust starting from the inlet of the muffler . If your exhaust has been replaced or modified previously fabrication to the existing exhaust on your truck may be necessary for the proper installation of our kit. trucks with modified suspension or body lifts may also require fabrication of the exhaust or truck for the proper installation of our kit. This kit has 2.5 inch Tail pipes included for increased flow . Standard flowing aluminized mandrel bend pipe is a standard feature as well. MagnaFlow XL 3 chamber mufflers use a unique combination of large-diameter perforated tubing and strategically placed sound baffles to reduce unwanted resonance and help your engine create horsepower. The sound baffles tune the sound waves using calibrated tuning gate openings that allow portions of the waves to pass through. These tuned waves reflect off the back wall of the muffler and cancel out unwanted harsher sounds. The large-diameter perforated core eliminates the flow restrictions of a louvered-style core. A careful balance between perforation size/spacing and the baffle tuning gate makes for great 3-chamber performance mufflers. Thisrear exit kit will come out directly under the rear bumper on each side of the truck.