Not a A-body,,,but an extremely rare mopar (* forest find !!!)

You definitely want to brace the unibody of that GTX with something and dig around and under it as much as you can. Looks like it's already somewhat collapsed in the middle and the doors probably don't close.

If it were me doing it, I'd pull the doors and weld some 1x1 tubing in an X across both door openings.