dumb drum

[4-speedfastback]

a couple of brake questions ? i am installing 11x2 1/2 rear drums on rear  and 11.75 big rotors on front using a m/c from a 78 Plymouth sport fury  disc/drum m/c . my questions are do i need to use the wheel  cylinders from a early 80's d150 and what are the part # 's  ?  my source for the rear drum  set up is from a 68 Plymouth gtx  .  part web sights  show different  part #'s for 11x 2 1/2 drums  68 Plymouth gtx and 70 coronet with  8 3/4 rear axle.  both are ribbed and look the same but says the are not interchangeable. sorry so wordy thanks for info in advance Tim