BD Diesel Performance Exhaust Manifolds have a perfect OEM fit for Chevy and GMC Duramax 6.6L Diesel applications and for the Dodge Ram Cummins Turbo Diesel 5.9L engines. Using this performance manifold will help to increase fuel economy, increase power and lower EGTs and has been proven through Dyno testing. The exhaust manifold has an easy no drill installation and is backed by a 1-year limited warranty.