Can anyone tell me what rear axle this is 8.2, 8.5 BOP or chevy?

 

It looks like an 8.2" Chevy,in an ElCamino.

 

I was able to find some numbers on it today. On the pinion side on the lower flange pass. side says GM 66, the other says 3969277NF. On the back side on the lower flange pass. side says K 51, other side says 490120 maybe and on the same side on the axle tube it says 07-880.

 

It's a c-clip 10-bolt Chevy rear.What car is it under.

 

It's a 68 GTO with crappy worn out air shocks and a different rear axle that I am trying to i.d. so I know what kind of aftermarket carrier and gears to make it a 3:55 posi. Nice looking car in that burn out pic by the way.