The new Flowmaster® Flow FX® cat-back exhaust system for the 2011-2019 GM Silverado/Sierra 2500/3500 HD trucks with the 6.0-liter engine is manufactured using durable 409 stainless steel throughout and features 3.50-inch mandrel bent pipes for better exhaust gas flow, and a Flow FX "straight-through" muffler is used for a moderate sound level and maximum performance. Maximum increases on the dyno revealed +21 hp and +23 lb-ft at the rear wheels. This system exits out the side, behind the rear wheel with a 5.00-inch black ceramic tip for added style and a custom look. The system uses all the existing factory hanger locations and includes installation instructions and all necessary hardware for an easy installation that you can do at home. This exhaust system was designed for Crew Cab Short Bed trucks with the 6.5-foot bed and is backed by Flowmaster's Lifetime Limited Warranty.