heater box

Yes they are the same . 73 They changed but will still fit. The hook is at a different location that holds it up at the vent. 67 -72 is under the door. 73-76 is in the door. Get the hook if you are using a 73 -76.
The '73 I purchased had 3 stud mounting for the fan motor, while the '71 I have has 4.......Firewall has 4 holes for fan mounting in my '71?