581230 or 621230 VOLTAGE REGULATOR. This is for 12 Volt systems, negative ground, 30 AMP. These are old stock and made in the USA. Fits:          

          1956 THRU 1958 CHRYSLER- ALL 12 VOLT.

          1956~1958 DeSOTO

          1956~1958 DODGE

          1956 HORNET

          1956 NASH AND PACKARD IF AUTOLITE EQUIPPED

          1956 ~1960 PLYMOUTH

          1956~1960 STUDEBAKER IF AUTOLITE EQUIPPED

          1958~60 WILLYS-KAISER JEEP DELCO EQUIPPED

          1956~1958 DODGE TRUCK

          1956~1960 STUDEBAKER TRUCK IF AUTOLITE EQUIPPED