Just something else to watch out for when swapping late and early parts. The 71-72 cars had smaller OD hubs than the 74-80 cars, not sure about the 73. So 71-72 brake drums will not fit on the 74-80 hubs. Also the 74-80 brake drums will not be centered if used on 71-72 stock hubs. Another result of the different hub OD size is that early factory steel wheels will not fit over the later larger hub.