I have driven manual disc Darts and Dusters for several years. Their braking abilities have always impressed me. Sure, you can get the wheels to lock. I never had a problem with the rears locking like I have read in magazines though. It was because of the great linear feel of the A body cars that I made the switch to a manual MC in 2012. I was really disappointed with the performance in the Charger though. I wrote that I had made several mistakes that collectively contributed to the outcome.
I tried 4 different master cylinders that all gave the same results: Hard pedal with poor results. My setup felt like a power brake car with zero vacuum to the booster. The smallest MC I used felt the best but it was still nowhere as good as the Duster/Dart setup using the same size MC.I put the power setup back on and added a vacuum pump.
Later, I was looking to improve even the power setup. I found some Carbon-Metallic front pads on RockAuto. I switched to 2.75 piston front calipers up from 2.6. I swapped in a brake pedal that I had modified for better pedal ratio. Then.....It did not occur to me that the disc/drum proportioning valve I had in there could be adding to the problem. I swapped in a drum distribution block and the brakes are fantastic.
I still want to try the manual setup again. I bought another 15/16" MC, the 4 to 2 bolt adapter and an adjustable brake pushrod from Dr Diff.