Tink,
Here is how I did it on the 85GL:
http://neksiwel.20m.com/cgi-bin/i/images/2gauges.jpg
Cheap parts from the hardware store.

On my current bus: http://neksiwel.20m.com/cgi-bin/i/images/fuelgauge.jpg
Here I incorporated a cut-off valve. My intention was to help smooth out the
pulses, hence cutting down on the gauge wearing out. Now I just leave it off
unless I think there's a fuel problem.

Ken Lewis
http://neksiwel.20m.com/