2001-2004 GM 2500HD/3500HD 6.6L LB7 Duramax Complete Transmissions

Whether you’re looking to upgrade to a high-performance transmission or to replace the worn out one in your 2001-2004 GM 6.6L Duramax, Alligator Performance has you covered with our complete transmission options. Our complete transmissions offer smooth gear shifts and upgraded flex plates to maximize the performance of your Sierra/Silverado 2500HD/3500HD. With brand-new, high-efficiency components, durable torque converters, and reinforced flex plates, your diesel truck will perform better than ever! Pair your new high performing transmission with our Crate Engines! GM Duramax Fitments: 2001, 2002, 2003, 2004 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.