1970 Duster Elephant ears. Where to mount alternator.

Old Mopar alternators are tough to mount on a motor plate since they are heavy and the mounting points aren't designed for plate mounting. Your job will be easier if you spend some time in a wrecking yard looking for a modern alternator that is small, lightweight and designed to mounted to a block or frame. Don't limit yourself to cars, sometimes tractor alternators will work or even stuff from construction equipment.
I thought about just buying a new alternator but from what I'm seeing for alternator mounts is guys going to a 1 wire alternator system.