Designed specifically for B & RB series Big-Block Chrysler engines the Performer RPM 230 cc Cylinder Heads are engineered to deliver the next level of power and performance. These premium cylinder heads feature high-quality components and precision machining to meet the demands of serious street and strip enthusiasts. Manufactured in Edelbrock’s ISO-certified facility in San Jacinto California each cylinder head is machined to exacting tolerances for exceptional quality and consistency. With larger 230 cc ports than comparable RPM heads and 73 cc fully CNC combustion chambers this new design is ideal for high-performance applications that require increased airflow and power while still maintaining compatibility with off-the-shelf components. These heads are intended for B and RB series Big-Block Chrysler engines not required to meet emission standards. Each Performer RPM 230 cc cylinder head comes fully assembled with premium valvetrain components including stainless steel one-piece swirl-polished intake and exhaust valves with undercut stems for improved flow manganese bronze valve guides ductile iron valve seats 2-ring positive oil control seals hardened steel valve spring locators and Edelbrock Sure-Seat valve springs retainers and keepers. Edelbrock’s patented Clean-Cast Technology further enhances performance by eliminating internal casting flaws and creating a smoother surface finish which improves airflow and coolant circulation. The result is increased power and better cooling right out of the box making these heads an excellent performance value for any Big-Block Chrysler build. For application-specific use Part 60025 is designed for Hydraulic Roller applications while Part 60029 is ideal for Hydraulic Flat Tappet setups.