I'm a newbie here, Hi to everyone.

I'm helping a friend with her 67 Coronet. After sitting for a few years we started it and the alternator bearing was seized. Bought a new alternator but now it seems to be overcharging. Is the regulator the most likely candidate?

 

67 should have a diode alternator. It could be the regulator. Remember rectifier alternators are for say 70-71 and above. Diode for older. The wrong combo can over charge.