I just swapped out the Carter P4070 electric fuel pump (72gph @ 6psi) for a Carter P4601HP (100gph @ 14psi), I have the pump deadheaded at the carb without the fuel pressure regulator and I'm getting 9psi at the gauge on the carb and the fuel isn't forced past the needle & seats.
This might be the solution to my problems. Also, I took the inspection plate off the P4070 and found the pump packed full of shavings from the foam inside the fuel cell. That would most definitely create a fuel delivery problem at higher rpm. I'm going to inspect the sump of the fuel cell and see if I have a clog there too that could explain only 9PSI being delivered from a 14 psi pump. If I do get the full 14psi I'll need to install the pressure regulator again.