converting a 2 door hardtop door into a 2 door sedan door

What you would end up with is your original sedan door with just the outer skin of the hardtop door on it. The entire inner door frame would be different as the sedan window frame is welded onto the lower door frame. Personally, I would keep searching for a 2 door sedan door. The Valiant and Dart front door skins were the same so a 67-69 Valiant door would be interchangable with a 67-69 Dart door. There were alot more 2 door sedan Valiants built than 2 door sedan Darts, so I would look for Valiant doors. Keep in mind that in 69, Chrysler changed the position of the door lock button on 2 door models. If you use a 69 Valiant or Dart door, get the parts that operate the door locks with it.