RS-X Spread-Port Aluminum Cylinder Head — Bare - PRE ORDER !!

Un-ported bare head casting; Valve seats and guides included, but delivered uninstalled; As-cast ports and chambers; Un-machined deck

The high-rpm airflow requirements of Pro Stock engines influenced the design of Chevrolet Performance’s RS-X spreadport Big-Block cylinder head design, which is used on the ZZ632 Deluxe crate engine. It uses a raised, symmetrical port design rather than the conventional Big-Block siamese design, for greater port-flow equalization. The heads are designed for large-displacement high-performance applications, where high-rpm airflow is a must for maximum performance. They’re used with a shaft-style roller rocker system. Assembled heads feature 2.450/1.800-inch titanium valves and beehive-type springs