2001–2025 GM 6.6L Duramax XDP HD Billet Coolant Block-Off Plate XD344

Eliminate rear housing coolant leaks for good with the XDP HD Billet Coolant Block-Off Plate XD344, engineered for 2001–2025 GM 6.6L Duramax LB7, LLY, LBZ, LMM, LML, and L5P engines. This precision-machined plate offers a permanent fix to a common failure point by replacing the factory cover that can warp or degrade over time. With its billet aluminum construction and built-in O-ring seal, the XD344 ensures a reliable, leak-free seal that outperforms OEM gaskets.

• Fits all 2001–2025 6.6L Duramax engines (LB7, LLY, LBZ, LMM, LML, L5P)
• Eliminates rear housing coolant leaks for long-term reliability
• CNC-machined billet aluminum for exceptional strength and durability
• Integrated O-ring seal for a secure, leak-free installation
• Black anodized finish for corrosion resistance and a clean appearance
• Direct-fit design reuses factory hardware—no modifications needed
• Backed by XDP's 1-year warranty against defects in materials and craftsmanship

Fitment:

2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 Chevrolet Silverado 2500 HD LT

2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 Chevrolet Silverado 2500 HD LTZ

2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 Chevrolet Silverado 2500 HD WT

2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 Chevrolet Silverado 2500 HD High Country

2020, 2021, 2022, 2023, 2024, 2025 Chevrolet Silverado 2500 HD Custom

2024 Chevrolet Silverado 2500 HD ZR2

2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 Chevrolet Silverado 3500 HD LT

2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 Chevrolet Silverado 3500 HD LTZ

2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 Chevrolet Silverado 3500 HD High Country

2011, 2012, 2013, 2014 Chevrolet Silverado 3500 HD WT

2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 GMC Sierra 2500 HD SLE

2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 GMC Sierra 2500 HD SLT

2011, 2012, 2013, 2014 GMC Sierra 2500 HD WT

2015, 2016, 2017, 2018, 2019, 2020, 2021 GMC Sierra 2500 HD

2020, 2021, 2022, 2023, 2024, 2025 GMC Sierra 2500 HD AT4

2022, 2023, 2024, 2025 GMC Sierra 2500 HD Pro

2024 GMC Sierra 2500 HD Denali Ultimate

2024 GMC Sierra 2500 HD AT4X

2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 GMC Sierra 2500 HD Denali

2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 GMC Sierra 3500 HD SLT

2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 GMC Sierra 3500 HD SLE

2011, 2012, 2013, 2014 GMC Sierra 3500 HD WT

2015, 2016, 2017, 2018, 2019, 2020, 2021 GMC Sierra 3500 HD

2020, 2021, 2022, 2023, 2024, 2025 GMC Sierra 3500 HD AT4

2022, 2023, 2024, 2025 GMC Sierra 3500 HD Pro

2024 GMC Sierra 3500 HD Denali Ultimate

2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 GMC Sierra 3500 HD Denali