4 wheel disc setup

[CoryM]

The metering valve controls how fast the fronts apply, and the proportioning valve controls how hard the rears apply. Metering valves are only used on disc/drum cars to compensate for the difference in bore size, and speed of action. Without either valve when you apply the brakes, the fronts would hit first, then the rears would lock up when they did come on. With your setup you don't need a metering valve, but you do need a prop valve. Your best bet is to plumb an adjustable prop valve in and set it up to match your car. Pretty easy, and fairly cheap. A factory prop valve might work, but chances of it being the correct one are minimal.
Cheers.