Its a GM Delco alternator so the regulator is internal. Its not a direct bolt in but if you can weld and cut, its not so difficult. Flip the stock small bracket, cut one ear off, and weld a cheap $10 mr gasket chevy lower bracket to the original, put a diode in the power wire to the turn on, run one wire for the sensing wire and you should be good since you have larger than stock wiring already.
This is on mine.
Just did my friend's 71 Demon this year as well...so better pics: