Alternator charging voltage high

Finally got my 318 running this morning. I checked the voltage at the battery (at idle) and it read over 15 volts. The battery by itself was a bit low at 11.9v. I assume the voltage regulator is going bad. What is the max charging voltage for a mopar alternator? Is 15.4 or so a safe charging voltage? I know the Chevy's charge in the low 14s max.
Ron
Its for a 1970 318 Belvedere.
Author: 1970ccc