The Edelbrock #61699 Performer RPM cylinder heads are designed for use with Windsor blocks including the 289-302 and 351W, allowing the creation of "Mock Boss" 302 or 351 "Clevor" Ford applications. The Edelbrock #61699 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. They also feature the highest quality intake and exhaust valves and valve springs. For use on pre-pollution controlled vehicles only.