Gene, hub pilot wheels center on the hub (think a shoulder on the brake drum that fits through the center hole on the wheel, like the rear brake drum fits over the axle). The part of the lug nut that sits against the wheel is flat, not angled like a regular lug nut.
"budd type" or "stud pilot" wheels have a larger hole that fits over the stud. That hole is beveled and so is the lug nut. The lug nut tightens into the wheel and centers it (like the old steel car wheels)
