Thanks John and Glen. I'm trying to add a spec sheet for the heads but site is NOT cooperating.
CASTINGS: Cast at local foundry in El Cajon, Calif USA
CASTING NUMBER: ECZ-G in original location 3/8" letters
COMPATIBILITY: All stock location externally. Will accept stock intake manifolds, exhaust, rocker arms, valve covers. Roller rockers will require different spacing due to altered valve spacing.
EXTERIOR APPEARANCE: As close to original as possible. Horizontal parting line like mid-1959 and later heads. Non-negotiable.
VALVE SIZE: 1.94" X 1.50 to 1.54". 11/32" single groove keeper, 45 degree seats.
AIR FLOW: Sample test head that ports were copied from: 255cfm intake 179cfm exhaust. Out of box est. 230int 170 ex.
DECK THICKNESS: .600"
HEAD BOLTS: 7/16". ARP bolts & washers supplied with heads. Modifications up to purchaser. Use of original head bolts will void any and all warrantees.
VALVE SPRINGS: 1.44" diameter 115# seat, chrome moly retainers, hardened & machine keepers, hardened spring cups
VALVE SEATS: Exact material to be determined. Ductile iron, powdered metal or ?
SPARK PLUGS: 14mm 3/4" reach. Moved .400" closer to exhaust valve centerline (away from intake valve).
COMBUSTION CHAMBER: approx 62-64cc. It is impossible to determine from the pattern. Only a fully machined casting can be checked. As pointed out earlier in this thread aluminum heads actually need a higher CR than iron heads due to heat loss. When feasible large chamber heads will be made available.
BARE CASTINGS: Will be available. Guide sizing and valve job un-finished.
ROCKER OILING: Stock. Haven't figured an easy way to oil stud mount rockers
WILL ANSWER QUESTIONS AS THEY COME UP
http://ford-y-block.com 20 miles east of San Diego, 20 miles north of Mexico