[RustyPile]

If your truck (you didn't mention the year) has the return line, then yes, you need to install the pump designated for that type system. Fuel formulation has undergone drastic changes since 1868. Modern fuel injection systems operation pressures are upwards of 5 - 10 times the operating pressures of the carburetor era. Today's fuel formulations are prone to vapor lock at carburetor fuel pressures. A fuel return system on these old vehicles is a good step toward preventing vapor lock..