A universal fuel-supply assembly is adaptable during manufacturing to be made for use with one of multiple different fuel types (e.g., gasoline or diesel fuel). A method for assembling a fuel-supply assembly includes providing a plate structure configured to be secured to a fuel tank. The plate structure has multiple bosses. According to one example, the method determines whether the fuel-supply assembly is for use as a diesel fuel-supply assembly or as a gasoline fuel-supply assembly. The method provides an opening through one of two different bosses that communicates with both the top side and the bottom side of the plate structure depending on whether the fuel-supply assembly is for use as a diesel fuel-supply assembly or a gasoline fuel-supply assembly.