Dave, Ford never made a 2WD Bronco- every one of them was a 4x4. However, the little Bronco II did come in 2WD or 4WD.

I'm curious about the center hole too. Are you guys sure the wheels were off Broncos and not the little Bronco II? If it was the full-sized Bronco, what year(s)? I've been thinking about changing rims and would like to avoid getting the wrong ones.