:JC, I won't speak to the valve block question. The master cylinder you have for disc brake application has different size outlet threads on purpose so the cylinders cannot be swapped on a stock unaltered car. The internal size of the piston is smaller for disc application than for drum and you will notice that the cylinders are not the same physical size. On my installation,I used an aftermarket adjustable valve because my tire sizes are no longer anything like stock. The stock valveing I feel is no longer correct for larger and different size tires front and rear. The way I dial the valve adjustment in is to do some light slides on a dirt surface the see what the rear is doing then dial in accordingly. Then do some braking on hard surface. Change setting a little until it feels like the car is being haulled down nicely and the rear is just at or slieghtly be low lockup.