??W2 Econo valves??

I have a set of w2 econo heads but I don't know if they take the long valves or the regular length valves. How do you tell? The casting number is 3870810E and they have the rocker stands cast on the head. Also, if they are long valve, who makes valves in this size? I am assuming that the long valves are 5.29 exhaust/5.28 intake, right?