There are other differences between the doors from different year Challengers
1970 doors are unique to themselves
- Specific to the glass; the glass has a different number of mounting holes (11 for 1970 and 9 for later cars) but still interchangeable.
- The upper stops and track bolt access holes were in different locations.
The 70 door panels used panels with a different number of panel clips.
- The door on the 70 Challenger had a single layer safety crash reinforcement bar, while later cars had a double and stronger crash brace in the doors.
Early Challengers used just oval holes to mount the whiskers, while later cars transitioned to screws. You can of course drill additional holes if needed.
- There was a window regulator change. They went from a plastic slider piece in the track to a bearing of some sort. Not sure when this transition took place but they added holes for adjustment.
I also think that the stops in the regulators themselves were in different locations (not 100% on this)
- The door handles are also different from the 70-71 cars to the later ones. The earlier handles were I think concave to follow the shape of the door while later doors used a flat door handle
- Not sure about the mounting holes for the mirrors. I believe the mounting holes were all spaced the same, but the mirror bases were a little longer on later cars.
The doors themselves are physically able to be bolted on to any year car but would require some modifications in switching over internal components.
Hardware, latches and regulators will work in all, though as mentioned above regulators and glass are not the same.
Information from my saved notes I gleaned from a number of sources over the years!
Hope this helps