I think a lot of people are too quick to abandon mechanical pumps.
A mechanical pump pumps more gas as the RPMs go up, a good thing.
A mechanical pump uses the cam motion not to pump gas, but to draw the gas into the pump, under the diaphragm, and it is the spring in the mechanical pump that pushes the gas to the carburettor needle seat. The pressure on the needle, from the float balances against the spring in the mechanical pump, and it all balances out. The spring only delivers gas into the carb when it is actually needed. On a factory system, the fuel pump cannot over-pressurize the needle and seat.
Your fuel level stays where it should be.