4.630 MLS Head Gasket .066 - BBC Brodix

The 4.630 MLS Head Gasket .066 from Cometic Gaskets is engineered for big-block Chevrolet engines equipped with Brodix cylinder heads. If you're building a high-performance BBC platform—whether for street, strip, or competition—this Multi-Layer Steel (MLS) gasket delivers the sealing integrity required to contain combustion pressures while maintaining precise deck height. Cometic has earned its reputation among engine builders and serious mechanics for producing gaskets that hold up under extreme conditions.

MLS gasket technology uses multiple thin steel layers bonded together, eliminating the need for retorquing and providing superior conformability to machined surfaces. The .066-inch compressed thickness is precisely calibrated for Brodix heads to achieve correct combustion chamber volume and piston-to-valve clearance—critical dimensions that directly affect compression ratio and engine efficiency. The 4.630-inch bore diameter matches BBC specifications, and Cometic's diamond-coated facing provides enhanced corrosion resistance and prevents micro-sealing failures common in conventional gaskets exposed to coolant and combustion byproducts.

Engine builders and mechanics working on carbureted or fuel-injected big-block platforms rely on this gasket when tolerance stacking matters. Whether you're assembling a 540-cubic-inch stroker or refreshing a vintage racing engine, proper head gasket selection is non-negotiable—it's the barrier between longevity and catastrophic failure. Installation requires clean decks, proper torque sequences, and attention to manufacturer specifications, but the payoff is a sealed engine that holds steady through thousands of heat cycles and high-load operation.