If You go to NAPA or mabe Your FLAPS they can get You a 12 volt motor the same size as Your 6 volt so that would be done I am not sure about heater core I know that places like Jimmy Carter sells them but there are a number of different heaters so You would have to match that up.There are after market under dash heaters if You do not care about stock they look like space heaters but smaller and would have 12 volt motor .


Pete