So just for the sake of double checking myself. On a mechanical fuel pump, the threaded outlet attaches to the metal line and goes up to the carb right? And the barbed one is the inlet from the tank?
Typically, yes.
Put pump in vise, and actuate the lever. Cover inlet or outlet while pumping it. You will know for sure. Im thinking i should do away with the electric and go mechanical. I will have to run a new line though.