SBM Performer RPM Cylinder Head - Bare

The SBM Performer RPM Cylinder Head is a bare aluminum casting designed for Small Block Mopar engine builds requiring high-flow intake architecture and precision chamber sizing. This is a dedicated performance head engineered for carbureted and fuel-injected applications where intake velocity and cylinder filling efficiency directly impact horsepower output across the RPM band.

Specification highlights include 2.020-inch intake valves and 1.600-inch exhaust valves, a 171 cubic centimeter intake runner volume, and a 63 cubic centimeter combustion chamber. The angle-plug design positions the spark plug at an optimal firing angle relative to the combustion chamber geometry, promoting more complete flame propagation and reducing quench. As a bare casting, final valve seating, port work, and assembly remain the builder's responsibility, allowing customization to specific fuel delivery and ignition systems. The 27.15-pound casting weight reflects solid aluminum construction suitable for both street and race applications.

Engine builders and performance enthusiasts working on Small Block Mopar platforms—whether 318, 340, or 360 cubic inch variants—select the Performer RPM head when maximizing intake efficiency within a naturally aspirated or moderately boosted power band. The 171cc runner volume sits in the midrange for port sizing, balancing low-end torque response with mid-range power delivery. Bare heads suit builders who perform their own valve work, port matching, and custom modifications or those integrating heads into race-specific applications requiring precise flow tuning.

Small Block Mopar performance heads remain popular in restoration hot rods, street performance builds, and vintage racing programs. The Performer RPM line represents a refined entry-point option for builders seeking factory-quality casting without assembled valve train or installed hardware, keeping total build cost controllable while maintaining flow and chamber efficiency standards.