2004.5-2005 GM Duramax 6.6L LLY Heads

Along with your truck's entire rotating assembly, the 2004.5-2005 GM 6.6L Duramax LLY Cylinder Head plays a vital role in determining compression while working with your camshaft and valvetrain to create the engine's power and torque curve. This is especially crucial when upgrading and modifying your engine as the stock head doesn't hold it's own during high-performance applications. Luckily for you, we carry a selection of aftermarket cylinder heads to dramatically improve airflow in and out of the engine so your Sierra/Silverado 2500/3500 can experience more power and accommodate for the various performance mods you install. Get the full potential out of your motor and let your engine breath easier with any of the aftermarket cylinder heads we offer here at Alligator Performance! 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.