4.200 MLS Head Gasket .051 - SBC

The Cometic Gaskets 4.200 MLS Head Gasket .051 - SBC is purpose-built for small-block Chevrolet engines requiring precision cylinder sealing at elevated compression ratios. This multi-layer steel (MLS) design serves both stock rebuilds and modified powerplants, making it an essential component for any engine builder or enthusiast tackling a serious SBC project. Whether you're restoring a classic or chasing power gains with a freshly bored short block, a quality head gasket is non-negotiable—it's the critical barrier between combustion and coolant passages.

The 0.051-inch compression thickness and 4.200-inch bore diameter are engineered to maintain proper combustion chamber volume and gasket crush, ensuring reliable sealing across temperature cycles and boost events. Multi-layer steel construction distributes clamping force evenly across the cylinder head and block deck, reducing hot-spot failures and blow-by that plague single-layer gaskets under stress. The MLS design also accommodates modern decking procedures and CNC-machined surfaces, providing superior conformability to imperfect mating surfaces while resisting deformation under sustained high-RPM operation.

This gasket is ideal for 350, 383, 400, and 427 small-block applications, particularly in engines with aluminum or ported/polished heads. Proper installation requires correct head bolt torque sequencing, clean deck surfaces, and appropriate fastener prep—skimping on installation protocol will compromise even premium gasket performance. Cometic's reputation in high-performance racing and street builds makes this specification a trusted choice for both turbo and naturally aspirated SBC platforms targeting reliable, repeatable power.