Hamburger's GM LS Lifter Valley Cover takes functionality and wraps it up in a high-tech, high-class package. This quality cover fits Gen III (non-DoD) engines and is milled from a solid block of 6061-T6 aircraft aluminum to tolerances only attainable through CNC machining. The 0.48" thick cover offers outstanding block rigidity while the machined underside provides an excellent seal using the existing factory O-ring. Wide chamfered edges ensure adequate intake manifold runner clearance. Includes stainless button head mounting screws. .