Serious engine builders, this Edelbrock Performer RPM cylinder head is what you need for some real power gains. The 95cc combustion chamber volume is perfect for performance builds without going too extreme. You get 292cc intake runners and 100cc exhaust runners that really help airflow. The valves are substantial too - 2.19 inch intake and 1.76 inch exhaust with 11/32 inch stems. Deck thickness is 5/8 inch for durability, and it handles up to .700 lift on the valve springs. Works with factory exhaust systems and aftermarket headers, which is super convenient. You'll need to use 3/8 inch pushrods with these, and they take standard 7/16 inch rocker studs. The manganese bronze valve guides and hardened steel guide plates are quality touches. These are bare heads though, so you'll need to do the final valve job and sizing for your specific setup. Recommended spark plugs are Champion RC12YC or equivalent 14mm with flat gasket seat. Perfect for 460 builds where you want reliable power without completely custom machining everything. Edelbrock knows performance, and these heads deliver exactly what they promise. Match them with Edelbrock head gasket sets for best results. Whether you're building a street machine or something more serious, these heads give you that solid foundation for making real horsepower. The quality is exactly what you'd expect from Edelbrock - no corners cut.