4.630 MLS Head Gasket .070 - BBC

The 4.630 MLS Head Gasket .070 by Cometic Gaskets is a precision-engineered cylinder head gasket designed for big-block Chevrolet (BBC) engines undergoing high-performance modifications. This gasket exists to seal the combustion chamber under extreme pressure and heat cycles, preventing coolant and oil leakage while maintaining compression integrity in stroker, boosted, and naturally aspirated builds. Whether you're restoring a classic muscle car or building a race engine, a quality head gasket is non-negotiable for durability and reliability.

Cometic's MLS (multi-layer steel) construction features three stainless steel layers bonded together with elastomer, offering superior compressibility and sealing performance compared to traditional cork or composite gaskets. The .070-inch thickness is engineered for engines with smaller chamber volumes or deck heights, allowing tuners to fine-tune compression ratios for specific fuel octane and boost levels. The 4.630-inch bore diameter matches BBC block specifications, and the MLS design resists deformation, chemical attack, and blow-by—critical when running high fuel pressure, nitrous systems, or turbocharged applications where conventional gaskets fail prematurely.

This gasket is ideal for serious engine builders, performance shops, and enthusiasts who demand repeatability and longevity in big-block builds. Installation requires proper head bolt torque sequencing and a clean deck surface; follow manufacturer specifications to avoid compression loss or gasket failure. The .070-inch thickness is particularly suited to high-compression stroker builds or engines where milling has reduced chamber volume—verify your specific engine's requirements before purchase to ensure correct thickness for your combination.