Got a 64 Plymouth and I am replacing everything on the fire wall. I called Mancini to get a new voltage regulater. He asked me if I had a single field or a duel field alternater. Uuhhh,eerrr,duhhh I say I dont know. How do I tell what I have or, what do I need to have. He said he has to know so he can send me the correct one.

if it is original it is single field.
duals didn't start till 70's.

one feild wire and one power wire

they have a solid state electronic voltage regulator that is a nice up grade for the single feild alt

drop the old points style VR for the newer one

best thing I did to my 68 dart with a single feild alt

stoped the amp gauge from discharging/jumping around at a red light in gear and stoped the headlights from dimming when in gear at a light

you can get it at napa for around 12-15 $