Billet Coolant Block Off Plate

Features:

• Billet aluminum construction for durability
• Integrated O-ring, no gasket required
• Eliminates common coolant leaks
• Thicker than factory plate design
• Direct replacement for OEM part numbers
• Precision machined for exact fit
• Corrosion resistant billet finish
• Designed for 6.6L Duramax engines
• Fits 2001-2025 Silverado/Sierra HD models
• Simple bolt-on installation
• Improves long-term engine reliability
• Backed by one-year limited warranty

Put An End To Duramax Coolant Leaks For Good

If you have ever dealt with a slow coolant leak at the rear of your Duramax, you already know how frustrating it can be to track down and fix. This billet coolant block off plate from Fleece Performance is built to solve that problem with confidence and keep it from coming back. The factory plate is known to weaken over time, which leads to seepage and repeat repairs that no one wants to deal with. This upgraded design is thicker and far more durable, giving you peace of mind every time you fire up your truck. Additionally, the integrated O-ring eliminates the need for a traditional gasket, which is often the weak point in sealing surfaces. Installation is straightforward, making it an easy upgrade when you are already working in that area of the engine. Once installed, you can count on a tighter seal and a cleaner engine bay without the constant worry of leaks. It is a simple upgrade that makes a noticeable difference in long term reliability.

Precision Machined Upgrade Designed For Long Term Sealing Performance

Built from high quality billet aluminum, this coolant block off plate is engineered to outperform the stock stamped component in both strength and sealing capability. The increased thickness adds rigidity, which helps maintain consistent clamping force across the sealing surface under heat and pressure. Furthermore, the integrated square cut O-ring is designed to provide a more reliable seal compared to traditional flat gaskets that can degrade over time. This design reduces the chances of coolant seepage, especially in high mileage or heavily used engines. It is a direct replacement for OEM part numbers 97941204 and 12698239, ensuring proper fitment on 2001-2025 GM Silverado and Sierra 2500HD and 3500HD models equipped with the 6.6L Duramax. The precision machining process ensures a tight, accurate fit that aligns perfectly with factory mounting points. Corrosion resistance is another key benefit, helping the plate hold up in harsh engine bay conditions. Backed by a one year limited warranty, this component delivers both performance and confidence where it matters most.

Fitment: 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Notes:

• Replaces known leak-prone factory rear cover plate
• Designed specifically for Duramax rear engine location
• Uses integrated O-ring instead of traditional gasket
• Ensure proper surface cleaning before installation
• Direct replacement for OEM part numbers listed
• Compatible with multiple Duramax model years
• Ideal during rear engine or transmission service
• Billet design differs from factory stamped steel
• Check O-ring condition before final install
• Covered by one year limited parts warranty