The Edelbrock #60367 Performer NHRA Stock/Super Stock Cylinder Heads are designed for use with 1982-95 50.L & 5.8L V8 applications. Cast and heat treated at the Edelbrock Foundry and machined at Edelbrock's manufacturing facility in the USA, Edelbrock heads are the best in quality and performance. All Edelbrock Cylinder Heads are designed from scratch using the latest in computer technology by our own highly skilled engineer's. Using highly efficient ports and state-of-the-art combustion chamber shapes, Edelbrock cylinder heads offer improved performance throughout the rpm range for great throttle response and top-end horsepower. Top-quality features include threaded inserts in rocker stud and exhaust bolt holes for superior strength and durability, and manganese-bronze valve guides with ductile iron valve seats. These are features that some other companies don't include!INSTALLATION NOTE: • Bare heads will have valve guides and seats installed, but will require final sizing and a valve job to match the valves you will be using. • 289-302 V8's require head bolt bushing #9680 and either head bolt kit #8552 (7/16") or stock bolts • Will not accept rail rockers. • Match with Edelbrock head gasket sets. • Recommended spark plugs are Champion RC12YC or equivalent 14mm x 3/4" reach with flat gasket seat.