Chevy BBC 454 1966-00 3/16" Thick Rubber Steel Core Valve Cover Gasket Set Blue They are manufactured from brass

They are manufactured from brass and include thread-in brass jet extensions (where noted)

Holley Performance Products and similar intakesOur Fuel Rail Kits include what is shown in the image

These chrome water necks from Speedmaster add a touch of class to your cooling system

They also feature precision-rolled threads

most notably the cylinder heads

Chevy BBC 454 1966-00 3/16" Thick Rubber Steel Core Valve Cover Gasket Set Blue They are manufactured from brassSpeedmaster 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