Today's tremendous power levels can be directly attributed to the excellent cylinder head designs on the market. In this case, we used Air Flow Research 210 CNC aluminum castings. Right out of the box, these heads are capable of big power in both normally aspirated and blown applications. For use with blowers, the decks are extra thick. Airflow is awesome at 210ccs on the intakes and the air/fuel mix comes through oversize 2.08-inch intake valves.