Need Tuff Wheel/Rimbow Adaptor

72dart said
After closer examination I notice that the one on the left has a notch down the side of the splines and the one on the right does not. Does this make a difference and if so which one will fit correctly on a 72 column.

One is for a truck, can't remember which is which but I think the one with notch or "key" in the splines is the correct one for cars.