2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Exhaust Manifolds & Up-Pipes

Enhance the performance of your 2004.5-2005 GM 6.6L Duramax with a premium exhaust manifold from Alligator Performance. Engineered to provide significant increases in horsepower and torque while reducing back pressure, these manifolds improve throttle response and help unlock your engine's full potential. Whether you're seeking stronger low-end power with a single-scroll design or top-end gains with a twin-scroll manifold, we offer a range of options to meet your performance needs. Discover the perfect match for your GM at Alligator Performance. Further enhance your diesels performance with Engine Upgrades!  GM Duramax Fitments: 2004, 2005 GM 6.6L Duramax. Submodel Fitments: WT, Custom, LT, LTZ, High Country, 1LT, 2LT, Pro, SLE, SLT, AT4, Denali. Some exceptions apply, please see individual product pages for specific fitments.