Ah, good, so you do understand that you just can't bolt the '73 bumper up to the '74 shock mounts. Using the '73 bumper either requires making a set of intermediate brackets to go between the shock mounting location and the regular '73 brackets to use the '73 bumper, or welding up and reinforcing the tail panel to match the earlier cars and using the '73 brackets. Getting the '73 bumper on is relatively easy, making it look factory requires a decent amount more work.