4.375 MLS Head Gasket .051 - BBC

The 4.375 MLS Head Gasket .051 - BBC from Cometic Gaskets is engineered for serious big block Chevy builders and engine rebuilders who demand reliability under high compression and boost conditions. Multi-layer steel (MLS) head gaskets represent the industry standard for modern performance engines, offering superior sealing compared to traditional composite designs. This gasket is essential for anyone rebuilding a BBC engine, whether for street performance, competition, or heavy-duty marine applications.

The MLS construction uses multiple layers of specially coated steel to create a consistent, durable seal that withstands extreme cylinder pressures and temperature cycling. At 0.051 inches compression thickness, this gasket is optimized for BBC applications requiring precise cylinder head height control—critical for achieving proper combustion chamber volume and compression ratios. The 4.375-inch bore diameter is engineered to fit standard BBC cylinder head bolt patterns, ensuring correct clamping force distribution and eliminating hot spots that lead to premature failure or blowby.

This Cometic gasket suits BBC rebuilds from mild street engines to turbocharged and supercharged applications where conventional gaskets fail. Proper installation requires clean cylinder head and block surfaces, correct torque specification according to your engine's manual, and use of appropriate head gasket sealant where specified by the manufacturer. Whether you're rebuilding a 427, 454, or 496 big block, this MLS head gasket delivers the sealing integrity and longevity that separates quality engine work from shortcuts.