Ford was always changing things, trying to improve stuff or to make initial assymbly on the assymbly line easier.

I don't know of any year that is exactly the same as another. There is always at least one change.

I'm pretty certain that you can use a 1982-up intermediate shaft and rag joint on the earlier 1980-1981 if you replace both as a set. The gearbox and steering column are the same, only the intermediate shaft and rag joint are different according to the books.