Difference B/W 70 and 72 Doors

[jmking9]

This might be a dumb question, but I did a search and couldn't find any answers. Other than the hole on the inside by the wing window, what is the difference between 1970 and 72 doors? Can you still use the steel door panels on a 72? And, if you can use the steel panels, do you have to use the 72 only internals? I have 72 doors that im going to use on my 70, and would like to stay away from the platic door panels if possible. Thanks