Tom:
You are correct - the head casting number is 3701887. The block casting number is 3701461 or maybe 3701481. It's really hard to see the numbers with the engine in the truck, and the 6s and the 8s look a lot alike. I think it is a 6 but I could be wrong.
Do these numbers tell us anything more?
I really appreciate your help guys, it's interesting digging up the past especially when old trucks are involved.
