64 valiant disc brake conversion

Found out the Lower ball joints I got in the buy were dust. BUT,my new old rebuild 10" drum lower BJ;s (that are perfect), just needed the mounting holes drilled out from 1/2 to 9/16 to receive the bigger disc BJ mounting bolts (drums are nut backed bolts, disc are threaded bolts) After speaking to a machininst, he told me it might be better to get a 9/16 to 1/2 stud instead of enlarging the hole to keep the integrity of the LBJ. Both are fine pitch I believe. I have the old disc setup so my uppers,sway bar tabbed LCA's and modded lower BJ's will work. That is huge as the LBJ's are $80 a pop now. Getting pads tomorrow and then on to my PST poly bushing master kit install. And Im losing 5 lbs of crusty road grime grease to boot!