64, 65, 66 Valiant doors will interchange within body style (2dr sdn to 2dr sdn, etc). The outside door lock hole is different, between 64, 65 and the 66. But it is no problem to modify the early hole to fit the 66 lock cyl. Never tried going the other way.
PS: The doors for the Valiant hardtop, will interchange with the Barracuda, but not the door glass, as the roof line is different. But the door glass can be swapped.
Just a FYI: 64, 65, 66 windshield is the same, and available new. 64, 65, 66 back lite are all different, and no known source, new.
PPS: The complete front clip can be swapped between all 64, 65, 66 "A" bodies.
Front fenders can be swapped on 64, 65, but the downward angled crease is different. 64, 65 hoods interchange with mods to the hood latch mechanism.
66 individual front end parts are 66 only, but as stated can be swapped as a complete front clip.
This is all Valiant/Barracuda info. I'm not up on Darts.
