Pumps either work or they don`t. How can you hear the pump at WOT? If they are noisy, some noise is normal, you could clean them by removing and running them backwards with diesel fuel. The pressure is controled by a regulator. The factory pumps will flow enough fuel. Your injectors will be your limiting factor and unless you dreams are to change the whole injection system ($$$$$$$$)

Did Clinton change his pump?

Tinker