Maximum competition, high torque, high compression low dome. 8000+ RPM, 500+ cubic inches. Dart developed the first successful aftermarket aluminum heads for the big block Chevy engine platform and we've done it again! We have continued to refine our revolutionary designs through our in house research and development program and now offer the latest of our advancements in the PRO1 20 Deg 440cc Aluminum cylinder heads. The Dart PRO1 20 Deg heads deliver superior performance, by utilizing 440cc runners in a raised asymmetrical port design, and feature a 20 Deg rolled valve angle with redesigned shallow combustion chambers. These heads are ideal for maximum effort naturally aspirated, big boost forced induction, or nitrous applications.