4000S fuel gauge question

[Dave Fain]

Does anybody know what the resistance values should be on the fuel level
sending unit on a 1987 4000S?  Mine moves all over the place while I am
driving but usually indicates about 1/2 tank right after it is topped off.
Shorting the wires to the sending unit makes the gauge peg so I think it is
OK.  I haven't taken the instrument cluster out to get at the voltage
stabilizer but I get a reading of about 10.15V through both the fuel and
temp gauges so I think it is OK.  I removed the sending unit, cleaned
everything with WD-40 and tightened up the wiper arm to be sure it was
making contact but didn't see any improvement.  I get about 36 ohms at the
top and about 300 ohms at the bottom.  Does anybody have a known good unit
they can check or know what the values should be?
thanks,
Dave