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

Hey there,

I've been working on converting my manual drums to power disc in my 71 Valiant and everything has gone together fine up until now.

The kit I used is the Pirate Jack Front Disc Conversion for small bolt pattern A body. The problem that I've ran into is that the spindle on the upper control arm ball joint isn't long enough for the castle nut to thread properly. I need about a half in, maybe a little less for the castle nut to thread enough to fit a cotter pin through. Does anyone have any ideas? I thought about using a stover nut or something instead, but that doesn't seem right.

Ideally there would be upper ball joints for stock 71 upper arms that have a slightly longer thread to allow the castle nut to properly fit.

Any help or ideas would be appreciated! Thanks