Chevy SBC 350 1955-85 Rubber w/Steel Core Valve Cover Gasket Set - Black They are heat-treated and threads

They are heat-treated and threads are rolled to provide up to ten times more fatigue strength

They feature very precise valve operation

They're available in both dual quad and single quad styles

Made from 5051 aircraft aluminum alloy

Chevy SBC 350 1955-85 Rubber w/Steel Core Valve Cover Gasket Set - Black They are heat-treated and threadsSpeedmaster valve cover gaskets are manufactured from high quality rubber, which is molded over and vulcanized to a rigid steel frame. They won't leak, blow out, or get sucked in, the way stock or inferior quality aftermarket gaskets can. These gaskets feature superior quality rubber and steel, which outlast cork and rubber composite designs to provide years of dependable service, especially if you frequently have to remove and reinstall the valve