Fuel Gauge Issue

There might be more truth to that!

If the resistance range of the Holley sender is such that it does not provide:

10 ohms full
23 ohms 1/2 tank
73 ohms empty

Note 23 is not 1/2 of 63.

The sender provides a curve to the gauge.

That being said if your sender is providing 50 to 80 ohms due to the fuel level in the tank it could be reading empty.

As for being 0 ohms (dead short) maybe you are pinching the sender wire under certain conditions.