BBM Copper Head Gasket 4.380 x .043

The BBM Copper Head Gasket 4.380 x .043 is a premium cylinder head gasket engineered for Mopar B and RB-Series engines demanding reliable sealing performance. This gasket delivers the durability and precision fit required by engine builders, restoration specialists, and high-performance enthusiasts working with classic Mopar powerplants. Built to exacting standards, it ensures proper compression containment and coolant passage isolation across thousands of heat cycles.

Constructed from professional-grade copper material, the BBM gasket features a 4.380-inch bore diameter with 0.043-inch compression thickness—specifications that match OEM requirements for Mopar B/RB applications. The copper composition provides superior heat conductivity and conformability compared to composite alternatives, allowing the gasket to maintain a consistent seal even under elevated combustion temperatures and varying clamping loads. The precision-engineered bore and thickness tolerance ensure optimal cylinder head-to-block interface contact, minimizing leak paths and reducing the risk of gasket failure over extended engine operation.

This gasket is ideal for anyone rebuilding or restoring a Mopar B or RB-Series engine, whether for street duty, vintage racing, or museum-quality restoration. Installation requires standard gasket replacement procedures and proper torque sequences to achieve the full sealing potential of the copper composition. A single gasket covers one cylinder head, making it essential to order the correct quantity for your engine configuration before beginning assembly.