but regardless, whether drum or disc, the odds of it being a 9 incher are pretty high? as it is a 302 granada Ghia "cruise-o-matic".. my only online resource for cars doesn't list rear end sizes but rather width.
by the way the 302 coming in the car (supposedly rebuilt only 1000 miles ago) is going to be "up for grabs" if you will... that is assuming you have means of getting it from central Cali to wherever you call home.. side note: up for grabs does not mean free... $$
Engine makes no difference. Last nine I saw was in a 1980 Granada (4 dr) had a six banger. It's pot luck as to what rear it'll have, but it's worth looking at every one you run across.