Maintaining consistent internal pressure and preventing leaks in your engine is made easy with our selection of 2011-2016 GM 6.6L Duramax LML Gaskets! Here at Alligator Performance, we offer an excellent variety of high-quality gaskets and gasket sets that range from basic stock replacements to complete performance upgrades. Our gaskets are curated from trusted manufacturers so you can outfit your Sierra/Silverado 2500/3500 with high-quality upgrades. Check out our full lineup of Engine Upgrades!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.