MLS Exhaust Gasket - BBC 1.920 Round Port

The MLS Exhaust Gasket – BBC 1.920 Round Port is a precision-engineered sealing component designed for big-block Chevrolet (BBC) engine builds where header-to-cylinder-head fitment demands OEM-level reliability. As a seasoned mechanic, you know that exhaust gasket failure is one of the most common culprits behind coolant leaks, performance loss, and incomplete combustion scavenging in high-performance and street applications. This Cometic gasket addresses that critical weak point with multi-layer steel (MLS) construction, engineered to withstand the thermal cycling and pressure differentials inherent in modern and classic BBC powerplants.

Cometic's MLS gasket technology stacks multiple hardened steel layers with elastomer facings, creating a superior seal that resists blow-out even under sustained boost or high exhaust velocity conditions. The 1.920-inch round port specification matches the intake and exhaust port geometry of classic BBC castings and modern aluminum heads alike, ensuring zero compression loss and eliminating the exhaust leakage that plagues conventional composite gaskets after thermal cycling. Unlike soft composite materials that degrade under repeated heat stress, MLS construction maintains consistent clamp load and conformity—critical for engines running in the 500+ horsepower range or those subjected to frequent street-to-strip duty cycles.

This gasket is ideal for BBC stroker builds, turbocharged applications, and restoration projects where header fitment spans multiple casting generations. Whether you're assembling a 427 big-block for a classic muscle car, upgrading a long-tube header installation, or chasing tighter tolerances on a competition engine, this MLS gasket delivers the durability and sealing integrity that separates amateur builds from shop-quality results. Proper installation requires torque-to-yield fasteners and sequential tightening protocols; always consult your cylinder head and header manufacturer specifications for optimal clamp load and longevity.