[rjSupra]

Ok, I'll call myself out and say that that was a stupid question. Either size would be fine. I never touched a suspension part in my life (hence the dumb question), and i just changed my lower ball joints using Mr Nickeleye's sticky FAQ on changing ball joints with his SHORT CUT method that works awesome! I did both sides ambling along in under 5 hours. Super easy job. I would recommend the smaller sized pickle fork, I could only find the larger one 15/16" locally and it worked fine, but I think you'd have more clearance with the narrower one.
It was super easy to get the castellated nut out (the 22mm nut), I used a cut in half combo wrench with just the 7/8" open ended wrench on one side (it was cut in the middle) with a cheater bar / pipe over it. On the other side, I merely used a long-ish stock 7/8" combo wrench with the box end side. They both popped loose easy. I did not use the doubled up 22mm and 19mm wrench Mr Nickeley describes - it actually did not make any sense or fit with the many combo 7/8" and 3/4" wrenches I had.
Bashing out, really just separating, the ball joint threaded stud (it looks like a large bolt sticking thru the hub / knuckle from that hub/knuckle part was super easy too with the pickle fork. F the SST tool, no need to waste money, my pickle fork cost $8.40 at my local Robbins aka Federated Parts. I barely broke a sweat on this job. Do it yourself, I saved $450 in labor charges and inflated parts costs. I got my two ball joints for under $90 delivered. There are two listed with JC Whitney, get the cheaper ones for MKIII Supras, all these parts fit great! This has been one of the easiest jobs I've done on a car in a long time. (Way easier than my recent coolant nightmare).