Finned 10 inch drums?

the 10in finned also came on some of the a body cars with the 7 1/4 rear end if it was a v8 car. I actually pulled mine off a couple days ago (70 swinger 318 car) while removing the rear 7 1/4 on my 70 swinger and they are exactly the same size as my 8 3/4 rear with 10in finned drums.