4.185 MLS Head Gasket .045 GM LSX RH

The 4.185 MLS Head Gasket .045 GM LSX RH from Cometic Gaskets is engineered for serious LSX engine builders and enthusiasts pushing high compression ratios and aggressive boost levels. This multi-layer steel (MLS) gasket is the right-hand cylinder head version, purpose-built for Gen III, Gen IV, and LS-platform engine swaps where OEM gaskets fall short of reliability demands. Whether you're rebuilding a performance street engine or preparing a dedicated track platform, this gasket delivers the sealing integrity required to maintain compression and prevent coolant leakage at the head-block interface.

Cometic's MLS design uses multiple layers of spring steel with elastomer coating to create superior conformability and load retention compared to traditional composite gaskets. The .045-inch thickness is precisely calculated for the 4.185-inch bore diameter, ensuring optimal clamp load distribution across the sealing surface without compromising head gasket volume or affecting compression ratio negatively. The right-hand (RH) designation ensures correct fitment for the passenger-side cylinder head, and the MLS construction maintains its sealing properties even under sustained high-temperature cycling—critical for turbocharged, supercharged, or naturally aspirated builds exceeding 400 horsepower. This gasket resists coolant and oil intrusion better than single-layer alternatives, making it the standard choice for engine builders who demand durability.

Installation requires proper head surface preparation and correct fastener torque sequencing to realize the gasket's full potential—neglecting deck cleanup or using incorrect head bolt tension will compromise sealing performance regardless of gasket quality. This gasket pairs with Cometic's left-hand (LH) counterpart to complete a full head gasket set for twin-head LS configurations. Professional engine builders, drift competitors, and dedicated enthusiasts performing significant displacement increases or turbo conversions standardly specify Cometic MLS gaskets as the non-negotiable foundation for long-term reliability. Verify your specific LS variant (LS1, LS2, LS3, LSA, L99, etc.) and confirm right-hand fitment before ordering to ensure correct cylinder head application.