MEMPHIS, Tenn. - Engineers at RHS have recently designed the only small block Chevy 23-degree cast iron head for 360-434 c.i. engines that is CNC-ported from the factory. The precision accuracy and durability of the RHS Pro Elite™ SBC 23-Degree CNC-Ported Iron Cylinder Heads are derived not only from the CNC-porting of the intake and exhaust runners, but the CNC-ported combustion chamber as well.

The CNC-ported 240cc intake and 85cc exhaust runners optimize airflow volume and velocity while the 53cc combustion chambers are also CNC-machined to relieve the valve shrouding that occurs when the edge of a valve is in close proximity to the combustion chamber wall. Overall, the full CNC-porting process provides more consistent runners and smoother port-to-chamber transitions, thereby increasing both airflow efficiency and horsepower.

In addition, these new heads from RHS are designed to use offset rockers in order to maximize the intake window at the pushrod opening for increased airflow.

As with the rest of the Pro Elite™ family, these SBC iron heads come with a host of unique features, including premium bronze valve guides and a multi-angle valve job. Also, ductile iron valve seats are inserted to better prevent seat and guide wear with alcohol and other racing fuel applications. The ductile iron 2.100” multi-angle intake and 1.625” radiused exhaust valve seats allow for superior airflow and improved atomization with racing fuels. In addition, the heads feature a refined water jacket for more even water flow to reduce hot spots in the engine. For racing classes that mandate the use of cast iron cylinder heads, RHS has designed the ultimate advantage by utilizing the latest in airflow technology.

• CNC-ported intake and exhaust runners and combustion chamber.

• Designed to use offset rockers.

• Premium bronze valve guides and a multi-angle valve job.

• Feature a refined water jacket to reduce hot spots in the engine.

For more information about RHS, call toll-free 877-776-4323 or check out www.racingheadservice.com online.