GM trucks built from the mid Seventies into the Eighties used a cap that looks very close to an A-body cap. The dead giveaway is that they will sit at a 45 degree angle from level when installed on a Mopar.
I'm aware of that. My plan is to modify a hardtop door if I am unable to locate a sedan door. I can take my window frame from the damaged door and weld it to to a hardtop door.