Whether you're looking to upgrade to a high-performance transmission or replace the aging one in your 2011-2016 GM 6.6L Duramax, Alligator Performance has you covered with our featured complete transmissions. Offering improved gear shifts and enhanced flex plates, these transmission builds are designed to maximize performance in your Ram 2500/3500. Equipped with brand-new, high-efficiency components, along with durable torque converters and flex plates, your diesel truck will perform better than ever—better than when it first rolled off the lot! Pair your new high performing transmission with our Crate Engines! GM Duramax Fitments: 2011, 2012, 2013, 2014, 2015, 2016 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.