Disc question

Bottom line is, check which ball joints you have before you do a disk brake swap so you know if you need new UCA's. Goes for everybody really, because you can find just about anything on a 50+ year old car and just because it's really old doesn't mean it's original.
this is the biggest takeaway.

just cuz it's there doesn't mean it's original or that it's right.

anything can happen in 50+ years.