Upgrade your 2001-2004 GM 6.6L truck with a high-quality single-exit exhaust system from Alligator Performance. Designed specifically for the GM 2500HD/3500HD, these aftermarket systems give your truck excellent performance and give your 6.6L engine a bold, aggressive roar. Precision-built from durable, premium materials, these single-exit kits optimize airflow for noticeable power gains. Many options also feature aggressive-style tips to enhance your truck's look. Whether on the road or off-road, these exhaust systems will elevate your sound profile while reducing unwanted drone. After upgrading to a single exit DPF-back exhaust, check out our selection of Air Intakes for further air flow and performance improvements!GM Duramax Fitments: 2001, 2002, 2003, 2004 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.