GM 10 bolt question

Picked up this rear for my '50 chevy truck today. Was told it's an S10. I'm thinking 2nd Gen Camaro. I know it has 2.73 non-posi. Looking for a positive ID. Any help greatly appreciated.

Axle tube #'s PAC 271
Diff housing #'s 1249518
R&P #'s 3984826(5) GM 9 75

outside drum to drum = 61"
Flange to flange = 55"ish

Note: Axle upside down

 

with those round cutouts it looks S10ish to me, is it a 7.5/7.65 ring gear? 2nd gen camaro would have an 8.2 or 8.5 and that doesnt look like either to me. Maybe a later corporate 8.5? I am not used to seeing those cutouts on one.

8.2 in my 47 cadillac



s10 rear in my buick



8.5 housing

 

I believe the S10 2WD is 54 3/8" and the 4WD is 59" wheel mating surface.

 

Looks exactly like the S10 rear in my T.

 

Hmm. Confused. It has the round shape, which leads me to 8.5". However the s10 8.5 axle tubes flare before they go into the pumpkin, mine do not.
If the above measurements are correct, mine doesn't match. The "PA" prefix on the housing should be 2.73 which is what I have.
I'm unaware of S10's having this ratio available. Not saying they weren't swapped out as this rear came from a '55 car.
Pic is of camaro rear (2nd gen). My spring perches match the pic as well.

 

if the axle tubes are smaller than 3" it mite be S-10, but don't think they came that wide.

 

They're 3" the whole length.

 

7.5 from a Nova, Ventura II, Olds Omega,Buick Apollo maybe? IIRC 75 and later used a corporate design rear end ***embly. Especially with the 9-75 date code on the R&P, probably 76 model year.

 

that is probably it, I ran into one of those oddballs once in all my years of swap meet shopping. Got one from a nova.

 

Not S-10 then

 

most likey one of these, the rearends got a bit wider in 75-on

 

Sweet. Now I'm getting somewhere. It has telltale signs of an 8.5 tho. Any way to tell for sure? Diff bolt size? Thanks for all the help guys.

 

open the rear and get the casting number off the carrier, then google it.

 

Will do. Searched forever for the housing casting #. Nothing. Everything points to gen 2 camaro/firebird. PA code is 2.73 in '75, R&P says '75, 10 bolts in '75 were 8.5". Center section style/shape matches 8.5. 61.5" outside width, 55.25 inside width, 45.25 spring pad width, 9.5" brakes all match camaro/firebird. I'm going with it.