Adjustable Proportional Valve - Do I need one?

I just completed my install of front/rear suspension and brakes on my 72 Dart and I am getting ready to bleed and align. Before I bleed, I want to ask a question: Do I need an adjustable proportional valve in the main rear brake line feed? I installed Dr. Diffs 11.75 front disk kit and a Right Stuff Rear Disk kit which is based on the GM screw type calipers. I also installed a late model aluminum master cylinder kit (1 1/32 bore). Car has manual brakes.

I dont run one on mine , just the orig. feed block for the old drum brakes .
Your master cyl. piston is too big -------------jmo