Mr. Gasket Performance Header Gaskets are manufactured from a heavy duty high-temperature material, .062 inch thick, consisting of an acrylic binder system to resist high temperature. Provides excellent sealing and durability with maximum torque retention to eliminate gasket failure. While precision die-cut for an excellent fit, it can be trimmed if necessary for modified port applications. For original equipment replacement, higher performance street, drag race and oval track use.

Fits Chevrolet 396,402,427,454 Gen IV Big Blocks with Round Ports up to 1.85 x 1.90 inches.