Oil Galley Plug GM LT1 Gen V 14-21

The Oil Galley Plug GM LT1 Gen V 14-21 by Melling is an essential internal engine component designed for modern GM LS-based and LT-series engine builds and modifications. This press-in o-ring style plug seals critical oil passages within the engine block, preventing unwanted oil leakage from factory gallery ports that may be unnecessary for your specific modification or performance setup. Whether you're performing a complete engine overhaul, upgrading to aftermarket oiling systems, or customizing your LT1 engine bay, this galley plug ensures reliable sealing and prevents pressurized oil loss during operation.

Manufactured by Melling—a trusted OEM and aftermarket supplier of engine gaskets and sealing components—this oil galley plug features a durable white plastic construction with an integrated o-ring seal, designed to withstand engine oil temperatures and pressure cycles common in high-performance applications. The press-in design allows straightforward installation without additional fasteners, and the o-ring creates a positive hydraulic seal that prevents oil weeping at idle and under full boost or boost conditions. At just 0.03 lbs with compact dimensions (1.6 x 1.55 x 3.55 inches), it's a lightweight yet critical element in maintaining engine integrity and preventing oil system contamination or loss.

This galley plug is ideal for mechanics, engine builders, and automotive enthusiasts upgrading 2014–2021 GM LT-series engines—including the LT1, LT4, and LT5 variants found in Corvette, Camaro, Cadillac, and Silverado platforms. It is particularly valuable when converting to dry-sump systems, installing remote oil filters, or blocking off unused gallery ports during engine modifications. Proper installation requires careful alignment with the gallery bore and appropriate seating force to ensure the o-ring compresses fully without damaging the plastic body. For best results, consult factory service manuals or your engine builder's specifications.