Mark, I am using one of the pollack 6 port valves two lines from tank to valve and one to fuel rail/ one return line from rail and two return lines to each tank. Feed and returns are selected in pair so you return to the tank you are feeding from. The valve also selects the sender unit from the active tank to send to fuel gauge. So far so good with mine. You have to be a little careful with wiring the gauge because there is one and only one way for it to work properly (I know from experience;-) BTW, it is rated to 90 psi.
PS The also make 3 port valves. I think they have around 4-5 different models.
[ March 03, 2003: Message edited by: Lynn Larsen ]