Alternator for 12V

This may be a simple question, but I'm trying to figure the AMP requirements for my 52 Pacemaker, manual 3 speed transmission.... no "power anythings".  The system was already converted to 12V. The Delco-Remy alternator in my setup has no part number that I can see. Just appears to be your typical alt. would imagine my amperage needed is not more than standard - but I'm not sure what that is.

Anyone have a suggestion as to a replacement model number. Thanks.