4.540 MLS Head Gasket .030 - BBC

The Cometic Gaskets 4.540 MLS Head Gasket .030 - BBC is engineered for serious big-block Chevy builders and enthusiasts who demand reliable sealing in high-performance engine builds. This multi-layer steel head gasket serves as the critical barrier between your cylinder head and engine block, preventing coolant and combustion gases from mixing while maintaining precise compression geometry. Whether you're rebuilding a stock 454, assembling a stroker motor, or refreshing a tired BBC platform, this gasket delivers the durability and consistency that professional machine shops and experienced shade-tree mechanics rely on for dependable long-term operation.

Cometic's multi-layer steel (MLS) construction uses precision-engineered laminations to create a resilient, reusable seal that resists blow-out under sustained boost, nitrous, or high compression loads common in modified BBC applications. The 0.030-inch compression thickness is designed to optimize combustion chamber volume and maintain proper quench characteristics without requiring custom piston work or head milling beyond standard machining practices. The 4.540-inch bore diameter matches the standard big-block Chevy block dimensions, ensuring a perfect fit across 427, 454, and other BBC variants without compromise or fitment concerns.

Ideal for street motors, race engines, marine applications, and high-output truck builds, this head gasket integrates seamlessly into any BBC rebuild where OEM or performance-equivalent sealing is non-negotiable. Installation requires proper surface preparation, correct bolt torque sequencing, and use of appropriate head gasket sealant per Cometic's technical guidelines to maximize longevity. Each gasket is individually packaged and ready to install, making it the go-to choice for builders who refuse to compromise on gasket quality during critical engine assembly phases.