If the tank is behind the seat, there is no gravity feed the carb if the fuel level is below the carb intake port, which I would bet is 99.9% of the time! The small pulse pumps do not hinder fuel flow when turned off, they are mostly used for priming as already stated. Just plumb into the lowest point of the fuel line and wire with a push button.
Joe
OK, so I took a little liberty with the "gravity feed" comment, but just how many inches is the carburetor bowl above the level of fuel with a full tank? The point is, the stock fuel pump does not have to work very hard to pull fuel from the behind-the-seat tank to fill the tiny carburetor bowl.
If one chooses to add an electric pump to their system to address a fault in the fuel delivery system or less than adequate starting system, or as a preventative for such issues which may show up in the future, that is their prerogative. Why would I argue against that? I would not, after all I converted one of mine to 12 volts just for the way that it turns the engine over twice as fast. I am simply suggesting that it would be a good idea to investigate why a truck does not perform as originally designed.
Carl
