tranny/engine swap info for Dodge trucks?
The engine mounts for the /6 are unique, so any truck prior to 86 or so with the /6 mounts will allow a direct bolt in.
You'll need a /6 bell housing for any stick shift trans, as well as the flywheel and clutch.
You may find that restoring the Dart is a far easier project than the truck you have in mind.
No matter what you decide, I'm sure someone on here has tried it and has good info.