Another bad voltage regulator?

Are you SURE it is not a grounded brush in the alternator? Try disconnecting the connector at the VR it should stop charging. Due to Chinoizaeazization no idea the good/ bad quality of replacements. OEM Chrysler VR's some of them lasted so long, vehicles ended up in the junk yard with the original VR Lots of em in fact

The other issue that can cause over-charging is poor grounding OF THE VR and voltage drop in the harness. The VR MUST see true actual battery voltage.

The last thing is a partially shorted rotor that will draw too much current. Look up in one of the late, say 73 service manuals over at MyMopar (free) There's a procedure for measuring rotor current draw