rear disc brakes vs rear drums

I have 11 3/4 discs on the front and 11x2 1/2 drums on the back of my 67 Cuda. It's all that I need, the drums work better cold and the discs better when hot. I haven't had any problem with the drums locking up and they aren't that much of a problem to change shoes. It's all Chrysler parts!!! The way Plymouth should have built a Formula S.