Edelbrock part #7241 Exhaust Gaskets are designed for 1958-1965 Chevy 348/409 W Series V8 engines. These Exhaust Gaskets are made of EnCore HTX-900; a high-density non-asbestos fiber/metal core composite material consisting of two graphite coated, heat Product Features:0.0625 in. Thickness1.8125 in. x 1.375 in. Port SizeWill Not Work On Factory Cylinder HeadsOnly Fits Edelbrock 348/409 Performer RPM Cylinder HeadsTwo Piece Configuration
