1965 plymouth valiant door

Doors are generally the same dimensionally from '63-'66 but there are differences. Convertible doors have a secondary alignment thingy on them that non-convertible doors don't have. However the minor differences don't mean you can't use other year/or even Dodge dart doors on your '65 signet convertible.

Indeed. the alignment "thingy." I am not sure if the wing vents are the same or not. Anyway, stripped down to the core, the same. I used a 65 Valiant 2dr HT door on my 65 Dart. Lined right up. There is a difference in the door locks, however, with the 66 Door having a different door lock opening than the 65. Best. sgrip65