in my southwind, this is how it is set up....
the 2 lines come out of each tank and go to an electic tank selector switch valve and feeds into one line
then into a fuel/water seperator
then into a electric fule pump
then into the mechanical fuel pump
yes, theres 2 fuel pumps....no sure why....some might say the electric is 'priming' the mechanical

i have no pressure regulator or gauge....i have no idea what my fuel pressure is....which does bother me and i plan on replacing the fuel line at the carb with a braided line/AN setup with a NPT port for a gauge to see where im at...and put a regulator in line as well.