2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Mufflers

Whether your diesel truck's factory muffler has seen better days, or you want to fine-tune it's sound, Alligator Performance is the premier destination for upgraded, universal mufflers that check all the boxes. We have a wide selection of different mufflers with a variety of internal designs, lengths, diameters, materials, exit styles, and finishes so that you can find the perfect muffler for your build. We have everything from ultra-quiet chambered mufflers, aggressive straight-throughs, and awesomely loud race mufflers, giving you a wide selection of options for your Cummins exhaust note. GM Duramax Fitments: 2004, 2005 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.