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.

[my67c20]

Looking for more info. Maybe this can also help others down the road. What is the major and minor diameters for the upper and lower ball joints tapers as well as the thickness for those areas. for a 67, 68, 69, 70, 71, 72

Ball joint measurements

67 upper. OAL 2.550, thread length 1", thread 5/8-18",taper length .750, minor dia .700 major dia .815

67 lower OAL 2.85, thread length 1.125, thread, .750 dia, taper length 1.15, minor dia .925, major dia 1.06

72 upper. OAL 2.750, thread length 1", thread 5/8-18",taper length 1.150, minor dia .625 major dia .815

72 lower OAL 2.85, thread length 1.32, thread, 11/16 dia, taper length 1.12, minor dia .880, major dia 1.06

These a from the parts i have on hand. Any body that can add to the list would be beneficial to others. Thanks