Maximum competition. High torque, high compression low dome. 8,000+ RPM, 500+ cubic inches. Race Series big block 18 Deg oval port heads bridge the gap between conventional heads and Dart's Big Chief heads. Utilizing Pro Stock style oval intake ports with 330cc or 383cc runners in a conventional asymmetrical port design, and featuring an 18 Deg rolled valve angle with redesigned shallow combustion chambers, this design is ideal for drag racing, marine applications and dirt modified classes permitting big blocks.