what is this rear end from??

hi i have this rear end in my 61 c10 im pretty sure it is not stock from what i know the truck had a gm 10 bolt from the factory

thanks for all the help

p.s. i have asked a few guys and everyone just says oh ya it is a gm 12 bolt i need to know what it came from im wanting to upgrade my rear brakes/switch from 6 to 5 lug

 

Scope out the tag and casting numbers. It helped me de-code mine.

 

what is the hub to hub dimension?

 

looks like a dana but not sure on the series?

 

Looks just like the 12 bolt truck rear in my friends 1967 Chevy short bed. Same suspension and pan hard too!

 

That's a 1964-up GM truck 12-bolt.
The Dana 44 has 10 bolts.
The '60-'62 trucks had either a drop-out center 10-bolt with a round bowl-like rear cover that bolted on, or the Dana 44.
The '60-'62 Chevy and GMC trucks had a pan-hard bar mount on a big bracket way in the middle of the passenger-side axle tube.
1963 was the first year for the 12-bolt, and I think it also had the panhard bracket in the middle of the tube, but the trailing arm brackets are different... different angle than the '60-'62 trucks.
The '64-'66 trucks (and maybe later) had a shorter panhard bar, mounted to an ear cast into the center section, as shown on yours.

Note that your panhard bar has been shortened.

-Brad

 

An old timer found me a set of 1974 chevrolet impala wagon axles in a 5x5 lug that fit my 1970 C-10.

 

thanks