2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Heads & Valve Train

The OEM cylinder heads on your 2004.5-2005 GM 6.6L Duramax LML are crucial for determining compression and shaping your engine's power and torque curve. Given the importance of cylinder heads, it's essential to replace them with a high-quality upgrade you can trust. At Alligator Performance, we partner with the most reputable brands in the industry to offer our customers the finest components for their vehicles. Maximize the potential of your GM 2500/3500 by investing in one of our premium cylinder heads today! Check out our full selection of Engine Upgrades for additional 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.