4.630 MLS Head Gasket .051 - BBC Brodix

The 4.630 MLS Head Gasket .051 from Cometic Gaskets is engineered for serious big-block Chevy (BBC) engine builders targeting the Brodix cylinder head platform. This multi-layer steel (MLS) gasket is designed for high-compression, high-horsepower applications where stock gaskets fail under sustained boost, nitrous, or naturally aspirated power levels. If you're assembling a street, strip, or competition engine with Brodix heads, this gasket delivers the sealing reliability required to prevent coolant leaks, combustion blow-by, and head gasket failure during extended hard running.

MLS gasket technology uses spring-loaded steel layers bonded to an elastomer core, allowing the gasket to compress and conform to surface irregularities without permanent deformation. The .051-inch compression thickness is a factory-spec dimension for Brodix cylinder heads and ensures proper combustion chamber volume and compression ratio stability. The 4.630-inch bore diameter matches BBC Brodix head geometry precisely, and Cometic's manufacturing tolerances prevent leakage at the critical deck-surface interface where peak cylinder pressures occur. Unlike older composite gaskets that require re-torquing, this MLS design maintains clamp load over hundreds of engine cycles, making it ideal for turbocharged, supercharged, or high-revving naturally aspirated engines.

This gasket suits builders working with Brodix BBC heads on applications ranging from street 427s to competition 496s and large-displacement stroker combinations. Installation requires proper deck surface prep—light honing to 32–63 microinches roughness—and torque-to-yield fasteners applied in three stages per the head manufacturer's sequence. The gasket is compatible with standard BBC engine blocks and pairs seamlessly with Brodix heads' raised intake runners and high-flow design. For any serious BBC project demanding reliability under sustained power, Cometic's MLS construction provides the margin of safety that separates street builds from race engines.