[Lynn Eades]

Mike C., If it is not a bunch of faulty switches, and you have toe board clearance, then there is another long shot. It might be that your m/cyl has the wrong spring. The residual line pressure valve holds around 1.5 psi. It is a one way valve that lets fluid pass through the ports in the valve when the brake is applied. On release of the pedal, pressure in the lines lifts the whole valve from the rubber seal in the end of the bore, against spring pressure, until the pressure drops and the valve lands back on the rubber seal, back into a state of equalibrium. If the spring is from a different set up, it might level out at a higher pressure. This is admitedly a long shot.
Btw. the residual pressure is important. It holds the cup lips against the bores and prevents weeping and it holds fluid in the lines to enable a quicker response/ better pedal.
I believe your issue to be one of the first two things.