LS Valve Cover Adapter Plates Small Block Chevy to LS HolleyHolley's new cast aluminum Ls valve cover adapter plates offer an innovative way to add the vintage styling cues of a 1958 1986 Small Block Chevy perimeter bolt valve cover to your modern Gm Ls engine. These adapter plates feature an integrated oil fill and are pre threaded for Pcv ventilation fittings. Simply install the Ls valve cover adapter plate onto your Gm LS1, LS2, LS3, LS6, or LS7 engine to serve as your true valve cover, install the coil