Do factory equipped vehicles always have same size drums front/rear?

I've only had a couple of 'A' body cars and have parted a couple and don't remember them having different diameter drums on them......oh well. Learn something new all the time. My 66 /6 Belvedere had 10's.....10x2 on the front and 10x 1 1/2 on the rear. My rears were grooved to the max and couldn't find any replacements in 1990 so I cut them myself. Took .100" out of them and they didn't clean up but ran them anyways until I could swap out the 7 1/4 rear for an 8 3/4. The over cut drums worked and never blew apart even after 'testing' them :D