Ball joint and spindle identification help

[my67c20]

Here is my drama. I have a 67 c20 that prior to my owning was switched from drum to disc on the fronts only. In the process of rebuilding the front end and not sure of what year ball joints i should use. I know its definitly not 67 (anyone need some). I went to Autozone and alll they had in stock was the balljoints for a 72. When i dry fit the lowers i think they fit good, however i am not overly sure about the uppers. With the nut lightly tightened i barely have the cotter pin hole open. The numbers from AZ are FA681 (upper) & FA997 (lower). I see from LMC that the 67-70 are the same for upper and lower and that they list the 71 & 72 the same for upper and lower.

For the upper i measured .650 - .815 & 1.41 thk
For the lower i measured .750 - 1.150 & 1.44 thk

How can i identify what i have? Would it make sense to have the spindles machined to match the 67? Any help is greatly appreciated.