GM/Dart LS Next MLX Head Gasket LH 4.200 .060

The GM/Dart LS Next MLX Head Gasket LH 4.200 .060 is a precision cylinder head gasket engineered for serious LS engine builds and rebuilds. Whether you're freshening a stock LS block, assembling a stroker platform, or completing a full engine teardown, this left-hand (driver-side) gasket is essential for maintaining compression integrity and preventing coolant seepage. Designed to handle both naturally aspirated and forced-induction applications, this gasket delivers the reliability demanded by mechanics, engine builders, and performance enthusiasts who refuse to compromise on quality.

Cometic's multi-layer steel construction provides superior sealing performance across a wide operating temperature range and varying combustion pressures. The 4.200-inch bore diameter matches factory and popular aftermarket LS cylinder heads, while the 0.060-inch compression thickness is precision-engineered to achieve the correct deck height and compression ratio for your specific engine combination. This thickness specification is critical—too thin and you risk insufficient sealing; too thick and you alter compression geometry and ignition timing. The multi-layer steel design distributes clamping load evenly across the bore while resisting blowout and deformation under sustained boost or high-RPM operation.

This gasket is ideal for engine builders, performance shops, and DIY mechanics tackling LS-series engine assembly or restoration on Gen III, Gen IV, or Gen V platforms. The left-hand designation ensures proper fitment on the driver-side cylinder head, making it essential when purchasing complete gasket sets for full-block builds. Pair this gasket with quality head bolts torqued to specification and proper surface preparation for optimal seal integrity. Installation requires standard engine assembly practices: clean, smooth deck surfaces, correct bolt torque sequence, and appropriate head gasket sealant if manufacturer-specified.