Fuel Gauge issue 82 C-10

[Bacca]

The fuel gauge on my 1982 C-10 only reads from half to empty. I have replaced the tank (small rust hole) and the sending unit. Wiring and the ground seem fine. Next obvious step is to replace the gauge but I'm not into replacing parts without knowing they are actually needed. I only did the sending unit because the tank was out.

Is there anything else I should be checking before ordering a new gauge?

PS: this truck also has a A/market electric fuel pump. I don't know if that could be a concern or not.

Thanks Bacca