4.200 MLS Head Gasket .030 - SBC

The 4.200 MLS Head Gasket .030 from Cometic Gaskets is a premium multi-layer steel gasket engineered for small-block Chevy (SBC) engine builds requiring precision sealing at the cylinder head interface. This gasket is essential for anyone rebuilding or modifying an SBC—whether you're restoring a classic muscle car, building a street engine, or creating a high-performance race platform. The .030-inch thickness sits at the thinner end of the MLS spectrum, making it ideal for applications where head deck height and compression ratio must be tightly controlled without sacrificing sealing integrity.

Cometic's multi-layer steel (MLS) construction uses alternating layers of stainless steel with elastomer coating to create a superior seal that flexes with engine movement while resisting blowby and coolant leakage. Unlike traditional composite gaskets, MLS gaskets maintain their seal integrity across repeated thermal cycles—crucial when running higher boost, nitrous, or sustained high RPM. The 4.200-inch bore diameter accommodates standard SBC cylinder spacing, and the .030-inch compressed thickness allows builders to maintain tighter tolerances on piston-to-valve clearance and overall compression ratio, which is particularly valuable in modified or stroker engines where factory deck heights may not apply.

Mechanics and engine builders choosing the 4.200 MLS Head Gasket .030 benefit from Cometic's proven track record in street, strip, and naturally aspirated applications—and increasingly in forced-induction builds where traditional gaskets fail prematurely. Installation requires clean deck surfaces, proper torque sequencing, and head bolts rated for the application (ARP fasteners are recommended for performance builds). This gasket pairs seamlessly with SBC cylinder heads from stock to fully ported castings and works with both cast-iron and aluminum block combinations, making it a versatile choice for any serious small-block project.