For upgrading or maintaining your GM 2500HD/3500HD's transmission, we offer a comprehensive selection of rebuild kits and internal components to make the job seamless. Whether you're looking to boost durability with a high-strength billet input shaft, upgrade to a high-performance overdrive clutch drum for handling extreme power, or refresh your transmission with new gaskets, bearings, and clutches, we've got everything you need! Give your transmission the upgrades and heavy-duty internal parts it needs to continue to perform flawlessly on your GM 2500HD/3500HD! Pair your new rebuild kits and internal parts with our selection of Engine Upgrades!GM Duramax Fitments: 2007, 2009, 2010 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.