I've never seen a year range on those trannies. I don't believe this one was used very long - it has the aluminum case and is a tower shift top loader. I'm guessing mid-late 80's. My tranny guy was surprised to find this in an 86 - his books showed it as an '87 (my truck was produced in Canada Oct '86 - so it was a very late '86)

Also I doubt you'll find it in anything heavier than a half ton 4x4 with 300/6 or small block V8