Dress up your GM 6.6L Duramax diesel engine with upgraded PPE Billet Aluminum Valve Covers. Available with or without pillars, these new valve covers are precision machined from billet to an overall thickness of .75 Inch/19mm, 6061-T6 aluminum on a multi-axis mill. The PPE Billet Aluminum Valve Covers are a direct, bolt-on replacement, which retain the factory gaskets, Bolts and grommets, and include a 7/8 Inch -14 O-ring boss-style crankcase ventilation port (port accessories sold separate). Non-pillar versions are available in your choice of black or gold anodized. Each anodized color option is available in a flat or satin finish. Valve covers with pillars are available in your choice of powder coated red, black or blue. You can also choose no color, and go with a brightly polished finish. Customize your engine bay your way. Complete that show truck look or simply replace that boring, scuffed up OEM cover. Whatever your build needs, these have you covered.