The very worst part of the drum brake system on these trucks is the stock master cylinder. I certainly would not attempt to use it with discs. I have installed a booster and upgraded MC with stock brakes on both cars and trucks before disc brakes were available and they operated much better. Do it right, use a dual diaphram booster, dual MC, and a proportioning valve and you will have great brakes.
The last booster/MC unit I purchased was under $300, well worth the expense.
Fred
Last edited by rfs56trk; 02/07/2018 5:11 PM.