DRD 42X37.5mm Performance Big Valved heads, 94mm bore (Built in the USA) (Dual Spring)

New DRD NON PORTED Performance big valved 42X37.5 heads, Stainless Steel valves, DRD dual springs,DRD CM retainers, DRD multi angle valve job. Intake and exhaust ports are casted 20% larger than stock, 53CC chambers. Intake port flow 132CFm @28 inches .500 valve lift, and exhaust port flow 102cfm @28inches .500 lift. Added material in the combustion chamber for deep fly cutting, and extra strenght. Head has small 12mm 3/4 reach spark plug to prevent cracking. The Price is for a pair heads, 2 cylinder heads. 94mm bore. These heads are same as our l5 cnc ported heads, minus tha port and cumbustion chamber machining.