both my hot rods have manual brakes,,my barracuda has been converted to 1973 and newer disc brakes 11 inch rotors,,and i have giant C body 11x 2 1/2 brake drums on the back, i run a 33 x 22 rear tire and the car weighs 3500 lbs stops great,,
my 1940 has chevelle 11 inch rotors(changing to ford or mopar rotors) up front and mopar 10x2 or 2 1/2 cant remeber out back,,manual works fine,, if your going with a after market cam,, ask what kind of vacuum it makes,,a lot of after market performance cams dont make enough vacuum to make power brakes work properly,,just my 2 cents