Brake size

1969 Dart, the rear is 8.25, front is stock with drilled hubs for 4.5". The drums all appear to be 10". The depth all look to be about 2.75". The rear overall height is a bit more, closer to 3.75, front overall height 3.25. I accidentally posted the specs for the rears before.
so, the 8.25 came in A bodies 73+ and in variety of other cars (as well as vans and trucks!), so there is a straight up wild amount of brake configurations in 10" alone, not to mention upgrading to 11"

the likelyhood is that it's an A body 8.25

for example:
on the 8.75 i have here it would take 10X2 brakes. the drum (inside face to lip) is measured as 10X2.25 and the shoe is 1.75

on the 8.25 i have the drum is 10X2.75 (a CH over) and the shoes are 2.5

so there are a lot of generalities thrown around in definition and use of jargon in regards to brakes. sometimes it is specified by drum size, sometimes by shoe size.

it's perfectly normal to hear: 8.25 w/ 10X2.5" brakes or just 9" brakes, thus indicating the smaller drum; just the same as that somebody would say: 8.75 with 10X2 drums although that would take a 1.75" shoe.

so, measure the diameter of the drum-- the ID of the braking surface, then measure the shoe. then compare that to the witness marks on the drum surface. that should tell you what you need to order.