Thanks for the reply. I think the regulator would not be solid state (appears to be the orig 1955 unit). I see your point using modern diodes and I'm sure it could work. One other issue is that I'm going to a neg ground system and the L-N alternator is a pos ground unit. I don't have enough knowledge to know what could be done to modify it. My other concern is that there is quite a mass of wiring under the hood and I would prefer to take it all out (charging system) and start over. Some of it appears original - some probably added/changed over the years. I have the orig wiring schematic from GMC - but the charging system was originally designed by American Lafrance, and I can't seem to find any schematics for it.
