George,
You are in the exactly opposite position I was in last Sunday evening when I decided to change the upper ball joint in my wifes 68 142. After I had pressed the new unit into the upper control arm I noticed that the taper was much to big for the spindle that the shank had to enter.
This was not a complete surprize to me as I do know of the differances between the early and late suspensions as it relates to interchangability. You must have the early version of the upper ball joint. I am of the understanding that this joint is no longer available and I think that the only solution you may have, if you do indeed intend to use this joint, is to make a sleeve. This should work fine and would be quite easy to do with the compound slide on any common engine lathe.
I was forced to find another method for my problem. In my Millwright tool kit was a bridge reamer that I had used for enlarging holes in the field when there was a misalignment situation. The taper is by chance just about right on and it was quite easy to enlarge the upper spindle hole to suit. My assumption is that I will use up every early style part I have and then convert as required into the future.
Let me know if you can look after this machining job locally without any difficulty, if not I am sure I can help.