What rear axle is in my 78 Caprice Classic Wagon?

Looking for information on the rear in my 78 wagon. 305 2bbl / th350. It's got the big 11x2 drums, an open carrier, and I think it is 2.93 ratio. So is this an 8.5 ten bolt or some other weird 8.75 twelve bolt I have read about? I ask because I am possibly looking to swap it out or put gears and a posi in it when I swap the engine and trans. Thanks in advance.

I had 2.73 in my 78 coupe 350 4 barrel car