My 65 coupe is on jack stands and all 4 wheel assys. are off. I noticed on the RF rotor assy. that there is a machined 5/8" hole right at the base of the hub where it meets the rotor. None of the other hubs has this hole. I'd post a pic of it if I knew how. I hope someone can tell me what this is from the description I have given. Thanks in advance......Bill