The glass, regulator, and most of the hardware are different too so you'll have to remember that on future repairs. If you've ever changed a '70-2 door glass you'll stay with the '73-6 doors. :banghead:
You can do it. I put 72 Demon doors on my 75 Duster. You will also need to change out the upper window channel and wetherstriping or there will be a big gap around the window.