---tab Description--- Description When you are pushing serious horsepower or building a show-quality truck, the factory cast aluminum valve covers just don't cut it. Under extreme heat and high-boost conditions, stock covers are notorious for warping and leaking. The SPELAB Billet Aluminum Valve Cover is engineered specifically for 2004.5–2010 GM 6.6L Duramax (LLY, LBZ, LMM) performance builds. Boasting a massive 19.5mm thickness, this CNC-machined masterpiece provides absolute rigidity and an unbreakable seal. The "Shaved" Advantage:We designed this cover with a sleek, shaved profile, intentionally omitting the bulky factory standoffs. This makes it the ultimate upgrade for trucks running aftermarket fuel systems (like FASS or AirDog) that have deleted the factory fuel filter housing. It eliminates the clutter, giving your Duramax that ultra-clean, custom-built look while offering versatile PCV routing options. Fitments 2004.5–2010 GM LLY LBZ LMM Chevrolet/GMC 2500HD 3500HD 6.6L Duramax Diesel EnginesNote: Ideal for trucks utilizing aftermarket lift pumps (FASS/AirDog) with the factory fuel filter housing removed. Key Features Massive 19.5mm Billet ProfileMachined from a solid block of aerospace-grade aluminum. Zero flex, zero warping, and a perfect mating surface that cures chronic high-pressure oil leaks common in high-horsepower applications. Shaved "Show-Truck" DesignA smooth, streamlined exterior without the ugly factory bracket standoffs. Perfect for trucks with relocated or aftermarket fuel filters, providing a much cleaner, aggressive engine bay aesthetic. Customizable PCV RoutingEquipped with dual fittings for total PCV flexibility. Allows you to easily run a custom reroute or connect to an external catch-can system, keeping oil vapor out of your turbo and intake. Superior Thermal CapacityBillet aluminum dissipates extreme engine heat far more efficiently than the porous factory cast covers, protecting your top-end components. Premium Anodized FinishAvailable in deep Black, striking Red, or classic Silver. Resists corrosion, oil stains, and fading, ensuring your engine looks as good as it performs. Specifications Material CNC-Machined Billet Aluminum Thickness 19.5mm Weight 6.19 kg Installation Location Engine top – replaces factory valve cover PCV System Dual Ports (Ready for Catch Can / Reroute) ---tab FAQ--- FAQs Q: Why upgrade to a 19.5mm thick billet cover?A: High-boost, tuned Duramax engines create immense internal pressures and heat. The massive 19.5mm thickness ensures the cover will never warp, flex, or lose its seal under extreme conditions, something stock cast covers struggle with. Q: Is this an ideal upgrade if I have a FASS or AirDog fuel system?A: Absolutely. Because aftermarket lift pumps allow you to delete the bulky factory fuel filter, we designed this cover with a "shaved" profile (no factory standoffs). It cleans up the engine bay perfectly and removes unnecessary clutter. Q: What type of gasket does this cover...