842 Aluminum head date question
 

I need help here guys. i have a set of 842 heads. one head has a 69 cast date the other doesnt. i am thinking its a service head. here are the numbers on this service head 5625 the other is 4025. are these cast date numbers, if so what date can you make out of it? i cant find anything else on this one head. can you help me out here. thanks