My 235 has the fuel transfer lines going up the left side of the radio
stack.  When a tank becomes dry, the bubbles are quite obvious, even
when not looking directly at the fuel line.
The pump is totally inaudible in flight.   I use a kitchen timer wired
into my intercom to remind me to check the header tank level so as to
avoid pumping fuel out the header tank vent.

This system has been very satisfactory, though I have changed the fuel
lines twice in 7 years because they begin to loose their transparency.

In the pictures of the panel you can get a glimpse of the fuel lines and
the header sight gauge on the right side of the stack.

      http://home.attbi.com/~rbelshe/

Bob Belshe
Moraga, Ca