4.540 MLS Head Gasket .027 - BBC

The Cometic Gaskets 4.540 MLS Head Gasket .027 – BBC is a precision cylinder head gasket engineered for Big Block Chevy applications requiring exact compression thickness control. This multi-layer steel gasket delivers the sealing integrity demanded by high-performance engine builders and professional machine shops working with BBC platforms. The 4.540-inch bore diameter and .027-inch compression thickness are critical specifications that must match your engine's exact machining tolerances to ensure proper combustion chamber volume and reliable compression ratios.

Multi-layer steel (MLS) construction provides superior durability compared to traditional gasket materials, offering improved sealing under the extreme pressures of high-performance and forced-induction BBC engines. The .027-inch thickness is a precise specification—deviations of even .005 inches will alter compression ratio and affect engine tuning calculations, ignition timing, and boost threshold response in supercharged or turbocharged applications. Cometic's manufacturing tolerances ensure consistency part-to-part, critical when rebuilding or freshening an engine that must meet specific performance targets. This gasket is sold individually, allowing builders to match the exact thickness required for their particular block, head, and piston combination.

This head gasket is specified for Big Block Chevy engines across multiple displacements and configurations—street engines, race applications, marine installations, and automotive restoration projects where factory specifications or custom build requirements demand a .027-inch gasket. Engine builders selecting compression thickness rely on Cometic's reputation for precision and consistency. Whether assembling a period-correct restoration or optimizing compression for modern tuning, this MLS gasket provides the reliability necessary for engines that will see sustained high RPM operation or significant load.