Will disc brakes help stop my rear wheels from locking up?

[1972K10]

I struggled with the same problem on my 72' and finally found that the rear backing plates had grooves worn into them where the brake shoes rub. I filled the grooves with weld and ground them down flat. Problem is entirely gone. Previous to doing this, I had tried everything and replaced everything nothing worked. Inspect you rear backing plates carefully for grooves. The surface must be absolutely flat for the brakes to move smoothly and work properly.