I learned something I didn't know tonight in trying to put new wheels on my '63 wagon. The left side has left hand threads. I knew Mopar did this, but not GM. Was this a Buick only thing, or did all GM cars of that era have them?
1963 was the last years for left hand threads for GM. Starting in '64 at GM they all went to right hand threads.
In my case, the nut holding the steering wheel. I was lucky, on our '62 LeSabre (sold). Someone on here alerted me about left hand wheel studs before I tried to remove the wheels.
Yeah, I learned that on my Riviera, too. Just go down to the parts store and get studs in RH that match what you took out and then you can get lug nuts in whatever style you need if you're doing custom wheels (I believe that's what you're going to do from your Member's Rides thread).