Hummdinger rear axle

Riddle me this guys...

I have a 12 bolts casting number (3969278NF) which has 10 bolts, and the closest thing I found was that it was used in Chevelles in 1970.
I've also been unable to find an axle code on the blasted thing.
The best part is that everything seems upside down on the axle, except the cover.

Only thing that is unquestionable in it is that it has an 8.5" rear end, the ring gear is an 11:37 (3.36 by my math) with no posi, and that this is all might odd for a Search and Rescue.

Any ideas for further identification?

I`m kind of lost, you say you have a 12 bolt with 10 bolts
the 12 bolts are 8.5 inchers and the 10 bolters are 8.2 inchers, very close but not the same.
how many bolts on the rear cover? is the cover round,if so
probably a 10 bolt, round with half moon notches on both
sides would make it an 8.2 bop axle, if it has 12 bolts and
is not round is probably a 12 bolt, the strongest of all.
can you post a pic of the cover should be able to tell from
that.

Sounds like you have an 8.2. Still parts available. However, please post some pics as the guys on this site know them by sight.