Squareback alt. OK on 71 Duster?

Ok the round back is a closed field 36 amp unit with one field wire ( green ). Your voltage regulator is mechanical . There are 2 ways to upgrade. Most common method is to upgrade to the later model solid state regulater which is cheap and available from any parts store. You would need the harness connecter for that regulator and an added piece of blue wire from that connecter to the altenater.
Second method is to buy a solid state black can regulater that looks and connects just like your mechanical stock unit. The second field terminal on the square back 60 amp alt would go directly to chassis ground.
This odd regulator is out there somewhere but I dont have a source suggestion other than ebay. Let me know which way you want to go and I'll answer any questions. Happy moparing.
p.s. electric fan that pulls only 16 amps ? Most can hit 30 amp draw. Varries with airflow restrictions.