Years ago, my '64 Polara was my summer drive to work car. I was also on the local VFD. One afternoon, my pager went off for a fire call 5 or 6 miles away and I had to use my '64 to get there. Drum brakes, no booster. After a series of stops and slow downs to make turns on this high speed run, I arrived at the scene pretty well out of brakes; real bad fade. I got stopped down the road a ways. It scared the crap out of me. I shortly installed front disc brakes from a 1970 Road Runner with Bendix dual diaphragm booster. I have had no problem since; 30+ years. When I bought my 1967 R/T, it had 11" drums all around with no booster. One of my first upgrades was to convert it to front disc brakes with a booster as well. The only way to stop one of these old B-bodies quick with drum bakes is to hit something.