Silverado Fuel Pump / Sending Unit

I'm planning to replace my fuel pump on my '99. Will this also take care of the gas gauge needle surging problem or do I need to also replace the fuel level sending unit? Does a new sending unit come with a new fuel pump?

Sending unit, fuel pump it is all a module, like $350. As for the gas gauge your stepper motors in the cluster may be bad. Why do you want to replace the pump?