2020-2026 GM 2500HD/3500HD 6.6L L5P Duramax Engine & Performance

More horsepower and torque is never a bad thing, and your 2020-2026 GM 6.6L Duramax L5P can easily achieve improved power, throttle response, and overall performance with a few aftermarket engine upgrades from Alligator Performance. We carry a wide range of parts including Tuners, Cooling Upgrades, Crate Engines, Gaskets, Engine Accessories and more, all designed to help you get the most out of your custom GM 2500HD/3500HD build. Some of these upgrades even help extend engine life for long-lasting durability, all while ensuring your truck can handle the amount of power being thrown down. And don't forget to check out our selection of 6.6L Duramax Transmission Upgrades and Exhaust Upgrades to ensure your truck is ready for any challenge you throw its way. GM Duramax Fitments: 2020, 2021, 2022, 2023, 2024, 2025, 2026 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.