If this helps: my cars' stock head is 4 valve per cylinder, each cylinder has a single port that has a divider going to each pair of valves. Ex: Each intake port and each exhaust port for each cylinder splits supplying the 2 valves for intake and 2 valves for exhaust.
My past discussions with tech type people is as long as the stock parts bolt up, and it is a 4 valve head, and has one port splitting to 2 valves (ex: not one port for each valve), it is OK. Aluminum, cast iron, all are OK.
Jeff