The Edelbrock #60769 Performer RPM Bare cylinder heads are designed for use with non-emission 1968-91 Chrysler 318-340-360 c.i.d. engine applications. The Edelbrock #60769 Performer RPM heads are perfect for street performance, daily drivers, street rods and muscle cars where seat-of-the-pants performance is needed. These cylinder heads deliver great throttle response and power from 1500 to 6500 rpm. For use on pre-pollution controlled vehicles only.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. • Delivers outstanding performance in non-emission 1967-91 Chrysler 318-340-360 c.i.d. engines • Make 417 horsepower and 397 ft-lbs. of torque on pump gas with an Edelbrock Performer RPM intake manifold and matching camshaft • The special valvetrain in the 1970 340 T/A is not compatible with these cylinder heads. Match with Edelbrock head gasket sets. • Recommended spark plugs are Champion RC12YC or equivalent 14mm x 3/4" reach with flat gasket seat. • Deck thickness: 5/8" • Pushrod diameter: 5/16".