RPM's go up, Fuel pressue goes down-Vol. 2

Ok let me see if I understand this. You may have 45psi at idle (isn't 51psi correct?) and everything seems fine even at low RPM revs. But when the RPM's start to raise to 3000 or higher the need for fuel is increased. Although the motor is trying to get more fuel, a blockage at this point would cause the pressure to drop dramatically due to the increased need for fuel and more fuel going into the injectors instead of the return. The reason I dont see a pressure problem at idle is because the need for more fuel is not present and the blockage is not so bad that is cuts fuel flow down at this point. So, my entire story comes to this. I do have a pressure problem when RPM's increase. Here is what I have done to my 87 SC so far:
New fuel pump, New filter, New regulator, New in tank filter (sock), checked all rubber hoses, checked fuel rail.
The only thing I have not checked is the metal lines or the injectors for a dripping injector. When I changed the fuel pump I had to clear the return line of the pump hanger assembly (in tank). My next step, or so I think is to remove my rail and see if once the system is pressureized if any injectors leak. If that does not solve my problem, I must have a blockage in on or more of my metal lines. Does this sound correct to everyone? Any better ideas? Feel free to give any and all advice you can. Thanks to everyone who has helped thus far.
Matt