The CJ:HP cylinder heads are available in either cast iron ($875) or aluminum ($975) The CJ:HP has Cobra Jet intake with high performance BBF exhaust ports. Like the F460 head, the CJ:HP also maintains OE 429/460 stock factory valve angles & spacing. CJ:HP cylinder heads use any standard 429/460 wedge flat top piston. OE 429/460 guide plates and stud girdles fit perfectly. CJ:HP flow numbers are indicative of very efficient CJ ports with intake flows capable of 350cfm @.600 and 375cfm @.900 with 2.25” valves (318cc runners). The BBF exhaust is capable of 210cfm @.600 and 250cfm @.900 with 1.71” valves (134cc runners). Has 74cc combustion chambers. Designed with engine builders in mind, CJ:HP heads may be purchased blank; i.e. no seats cut or guides sized.