Proportioning valve

[Silver R/T]

I want to put disc brake kit on the front of the car. Do I have to run aftermarket proportioning valve or not? Isn't there factory proportioning/distribution block mounted in engine bay from the factory?

[JB400]

I want to put disc brake kit on the front of the car. Do I have to run aftermarket proportioning valve or not? Isn't there factory proportioning/distribution block mounted in engine bay from the factory?

No, you don't have to run an aftermarket proportioning valve unless  you just want to be able to adjust them.  It depends on your brakes.  You do have to switch  proportioning valves to one that is made to work with disc brakes though, other wise some of your wheels will lock up first, making for an interesting ride.   

[BrianShaughnessy]

I run the old drum brake distribution block with an adjustable in the line to the rear on my 4 wheel disk setup.

For disk/drum I was just running a factory disk/drum combination valve.

[Silver R/T]

Mine has drums on all 4 corners

[bill440rt]

Depends on what "kit" you buy.

I have a 4-wheel Wilwood kit, I used a GM-based disc/disc valve with built-in proportioning. No adjustable valve.
I also have a manual front disc kit on another car from Master Power, I kept the drum valve but added in a factory style repro disc hold off valve just behind it.

Brakes work fine in both cars now.