Fuel Gauge 1997 chevy truck k1500 does not working corrrectly. The complete assembly was replaced in the tank (other reasons) and the fuel gauge still reads incorrectly.

Where did you obtain your replacement unit? New or used?
Some of the original fuel level senders have been determined to be subject to significant inaccuracy. A revised part is available.

Other issuse could be poor/faulty connections between the tank sending unit and the instrument panel cluster (IPC), or could also be attributed to a faulty IPC.
A signal generator can determine the validity of the fuel gauge reading. Proper diagnosis will pinpoint your vehicles fault.

Thanks for the reply CaptainRich! It was an aftermarket from Advance Auto Parts. I forgot to mention the Temperature Gauge doesn't work either. Is there a ground connection for the instrument cluster that may be loose? The wires to the battery were all cut at one time, so perhaps a ground wire is missing from the battery?

The Temp gauge receives its ground through the coolant temp sender mounted on the engine. The fuel pump and sender share the same ground: G103 which is also on the engine, next to the thermostat housing.
From the battery Negative terminal there should be two wires: one large high-amperage that attaches directly to the engine, and a smaller wire that attaches to the vehicle body (usually on the inner fender near the battery).
It would be nice to find a loose/corroded ground connection somewhere, but with two gauges inop, I tend to think you have a failed IPC.

Why the fuel gauge on my 1997 chevy siverado always move when I stop and go, or like when I go over a bumb?