Dear Cletis;
Good point. I guess I was focused on the resister issue(s).
The early alternators (1963)with external regulaters were adjustable though. Today, most use the "one wire" unit as the regulater is built in.
I personally use a 12V generator/regulater so I can keep stock amp guage and 'orginal look'.
The smallest "one wire" Alt. is 60 Amp & will 'toast it' etc.
