Performer RPM rectangular-port heads have specially designed intake and exhaust ports for increased flow and velocity over standard big-block heads. These heads feature a highly-efficient 118cc open-style combustion chamber and high-velocity 315cc long/300cc short intake ports. Designed for street/high-performance big-blocks operating from 2500-7000 rpm. Stainless steel, hardened tip 2.19" intake/1.88" exhaust valves have 11/32" valve stems for excellent flow and lighter weight. The deck surface and water jackets work with all generations of big-block Chevy blocks. Heads include top-quality ARP rocker studs, bronze guides and hardened, ductile iron valve seats.

NOTE: This product is not legal for sale or use on pollution controlled motor vehicles.