Intake runner: 170cc, Exhaust runner: 60cc, 70cc combustion chamber, Straight style plug. Part number of exact heads new in Summit is EDL-607319, for $590ea. plus Crane Energizer Roller rockers CRN-11744-16 new for $196, plus all the port work. Over $1600 invested, take it for half price. By the way my location is Tonawanda, NY. North of Buffalo, area code 14150. Thanks. Let me know.