Performance Header Gaskets Fits 1955-1987 Chevrolet 262-400 Gen I Small Block Round Ports, 1.625 Inch Mr GasketManufactured from high temperature composite exhaust material. Provides maximum torque retention to eliminate Gasket failure. Can be trimmed if necessary for modified port applications. Precision die cut for an excellent fit. For OE replacement, high performance street, drag race and oval track. High Temperature Exhaust Material Withstands Extreme Exhaust Heat Provides Excellent Sealing And Durability Superior Tensile Strength Resists Deteriorating