Now it was time to turn our short-block into a full-fledged engine. First up, was bolting on the Racing Head Service (RHS) 180 heads (PN 12052-01, $609.00 each). These Pro-Action 23-degree heads feature a 64cc chamber and come fully assembled. RHS advertises that the peak airflow, at .700-inch lift, is 270 cfm on the intake and 195 cfm on the exhaust. If you need to save a few bucks, and don’t mind the extra weight, RHS also offers these heads in an iron version (PN 12317-01, $461.95 each). For head bolts, we went with a kit from ARP (PN 134-3601, $73.48).