AFR ELIMINATOR Series Small Block Chevrolet 23° heads feature 5-AXIS CNC shaped intake and exhaust ports as well as highly modified combustion chambers. The exhaust ports are also spread apart approximately .500 compared to the standard location and feature a Stahl bolt pattern. All are available in street and competition versions. The 210cc, 220cc, 227cc, 235cc, and 245cc Small Block Chevrolet heads are designed for aggressive, non-emissions compliant, street or race applications. Spread Port or Gen II LT1/LT4 versions are also available.