Rad...fan clutch...both, all of the above
I tried to skirt around the same issue myself, cost me a head gasket, rebuilt engine +.
I ended up with a good engine, 2 electric fans, reconfigured vacuum lines, plus an education!
Finally, just when I got it painted and brakes done... I pulled out of the garage and a guy slammed into me, totalling the car!
Ended up learning lots about these cars, lessons learned and paid!
Bought what I thought to be a parts car (sight unseen), it turned out to be a minty '82, my daily driver, and lotsa spare parts to boot!
Every dark cloud has a silver lining.