on a 3.2 fuel comes from the pump to the bottom of the filter,
top of filter to the front of bothe rails,
end of one rail is stock FPR,
end of other rail stock damper,
at the bottom of the stock FPR is the return, excess line that normally connects to the return line to the tank,
#2027 FMU intercepts there, to the in port on the FMU,
the out port on the FMU connects to the soft/hard line to the tank
the fmu just blocks off the return line at a rate relative to the boost signal the fmu receives from a port under the butterfly on the TB.
don't know if that helps you. depends on what you got going on as far as how much 3.2 stuff you're using.