4Piston Racing CNC Ported cylinder head. Pro156v2 CNC ported intake and exhaust ports. Oversize steel intake valve seats to suit +1mm intake valves, manganese bronze valve guides. I bought this and is now no longer needed. Its still in original packaging and has not been opened. The NEW Pro 156v2 CNC cylinder head is the ultimate cylinder head for your street car. The original Pro 156 raised the bar and set the standard for entry level street cylinder heads by offering the highest quality in the industry and airflow that surpassed many very expensive race heads. The newest version of this head takes it a step further with improved airflow…