Upper control arm ball joint spindles not long enough on disc brake conversion

The issue you raise is definitely particular to that Pirate Jack kit. I just recently worked through the same conversion with that kit. And it has those locking nuts. You use those with the sleeves for the upper ball joints. I didn’t like the look of that so I just bought new UCAs with the bigger ball joints. A few other guys have used that Pirate Jack kit on FABO and they haven’t had any problems with that lock nut that I have heard. You just have to get that nut on far enough to be flush with the end of the ball joint stud when tightened.