RBP’S heat treated, black coated exhaust systems include 4” mandrel bent stainless steel tubing made to fit the 2007.5 to 2008 Chevy and GMC 6.6L.  This system also includes the black tip. Since this exhaust system fits in existing OEM hangers, it is easy to install and is the best fitting system on the market.  This black coated system helps lower exhaust gas temperature which helps increase fuel economy, horsepower and torque but will not void your factory warranty.