If you're regularly towing near the GVWR or GCWR of your 2007.5-2010 GM 6.6L Duramax LMM, you're likely going to need to upgrade your truck's hitch. A new Class III hitch is stronger and more reliable than the factory hitches seen on some GM 2500/3500's, and will last longer while delivering a better towing experience compared to the weaker factory hitches. For those constantly towing or hauling heavy loads, an aftermarket hitch can make all the difference. 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.