The Stovebolt Site Forums The Shop Area General Truck Talk Proportioning Valve necessary for front disc brakes?

I use a Mustang II dual master cylinder without power assist, disc front, drum rear. The line going to the front is 3/16" (if I remember right), and 1/4" to the rear. Been running this for 10 years of almost daily driving and the brakes have worked great in all sorts of stopping circumstances.