Devin pretty much summed up my feelings about manual brakes on the AD truck. My 54 is using a disc conversion on the front with drums on the rear, with an adjustable proportioning valve so I can fine-tune the bias as driving conditions warrant. Feedback is good and the system is simple. I used a late 60's Corvette manual disc/drum master which was surprisingly inexpensive and locally available. If you want to check out parts or applications I like:
www.rockauto.comDave