4.540 MLS Head Gasket .089 - BBC

The Cometic Gaskets 4.540 MLS Head Gasket .089 is a precision cylinder head gasket engineered for Gen V and Gen VI big block Chevy engines. This multi-layer steel gasket delivers the compression seal integrity demanded by high-performance BBC builds, whether for street engines, racing applications, or rebuilt stock platforms. The 0.089-inch compression thickness is optimized to achieve proper combustion chamber volume and maintain critical peak cylinder pressure for reliable operation across a wide power range.

Multi-layer steel construction provides superior gasket durability and thermal stability compared to traditional composite designs. The 4.540-inch bore diameter matches the deck specifications of Gen V and Gen VI BBC architecture, ensuring a precise fit that minimizes leakage and prevents combustion gas escape. Cometic's MLS technology uses embossed steel layers with elastomer coating to maintain a reliable seal under sustained boost, high cylinder pressures, and thermal cycling—critical factors in forced-induction and naturally aspirated performance engines. The specified compression thickness directly controls chamber volume, affecting compression ratio and combustion efficiency, making precise gasket selection essential for engine tuning and reliability.

This gasket is essential for builders and technicians performing big block Chevy rebuilds, stroker assemblies, or refreshes on Gen V/VI platforms. Whether you're assembling a traditional BBC for towing and truck duty or a race-prepped engine for competition, proper head gasket selection is non-negotiable. The 0.089-inch thickness should be verified against your specific build specifications, intake manifold gasket thickness, and desired compression ratio to ensure correct deck height and chamber volume. Each gasket comes individually, allowing precision replacement or stocking for multiple engine builds. Pair this with quality fasteners, proper torque sequences, and appropriate sealant for maximum seal reliability.