I wrote earlier in this thread that I installed a pair of MCQUAY-NORRIS FB290, well, I did, but those are the upper arm bushings. I did also buy a pair of MCQUAY-NORRIS FA395 - those are the upper ball joints. I did install them, my arms were sand blasted but otherwise nothing else done to the threads, they went in ok, I guess tight for most of the threads and then really tight for the last 1/2 turn. I see that rock auto is no longer showing the FA395 so I don't know what's up with that.
The taps - are really expensive? Like $200+ ? Rock is showing a dozen different ball joints, most are under $15, you might want to buy an assortment and try them vs buying a tap.
PS: Rock describes them as "front upper, with drum brakes". I don't see any listed as "front upper - with disk brakes" but maybe that's because there is no difference? Or there is a difference, and you can't get them any more?