Electronic fuel pumps were never used originally but are required in some circumstances, mainly when later downdraft carburetors are added. This is a quality 6-volt Carter brand pump rated at 4psi.  If you're using a carburetor that needs lower than 4psi, you'll need to add a regulator between the fuel pump and the carb. Regulator is part number A-9350. This pump will work in either positive or negative ground applications.

Note: Fuel pump does not act as a shut off.  When pump is not running, fuel will still pass through.