You don’t need to change upper control arm on that 69 B-body to do a factory type disk swap.
All E and B bodies have large ball joints. /6 to Hemi. And they share the same upper control arms.
60-72 A-bodies all have smaller upper ball joints than B and E bodies. And the 60-72 upper control arms have a smaller hole to accept those smaller upper ball joints.
1973-1976 A-bodies with large bolt pattern disk or drums got larger upper ball joints and new upper control arms with larger holes to accept them. *Use these upper control arms when converting to A-body disk spindle or FMJ body disk spindle
1973-1976 small bolt pattern cars with 9” drum got the old small ball joints and upper control arms.
