sorry 1200rallycar but i think you might be a bit missleading ,the wheel bore size should locate on the axle / hub spiggot diameter ,the fillet radius on the axle is there for a reason and thats why the wheel has a corisponding chamfer on its bore ,to clear the rad ,as for the size of the location dia you should get this measured as they can sometimes be different if for example you have later model discs on the front and std drums on the back . if you run with no location dia the studs are the only form of radial location ,this is not always correct and wheel vibration and even wheel loosening can result