Bulkhead Instrument panel bypass.
Don't just "get a 72." You need to make sure it's a SQUAREBACK, and not a ROUNDBACK. The newer squareback was the improvement. "The thing is" rebuilders cannot be trusted
ALWAYS check the field circuit continuity before hooking up. MANY rebuilds come with at least one--and sometimes both--brushes grounded.
If you are using the 69/ earlier VR you can use either an earlier or a later isolated field alternator.......simply ground one field connector