The # bad Merc directed you to should tell you what year it was "first" made,but you will need to get the casting date codes to see what year it actually is. The Block number he referred to is straight upward from the starter. If you lay under it and look up you should be able to see it. Ford used a common casting # on their engine through several years and the suffix tells what incarnation it is. It could have a D6 (1976) casting # but be a '79.
hey,woodz428, it's just a coincidence, I've had the name since the early 60's when I came back from Nam in 71 I was passing a record store in NY and I saw an album in the window by a group called JoJo Gunne it was strange, I mean spelled the same and all, strange but they were good and gone in a flash but I'm still rockin, later JoJo