Yet another Rear End ID

[kingburnett]

I need help identifying the rear end on my 1961 K10.
I know that it is not the original.
The cover on the rear has 12 bolts. The Axels have 6 lugs each. I took off the drum and and measured driver side shoes to be 2-inches wide.
The self adjuster is installed wrong.
Other markings on the drum were:Centruy max dia 11.060 Z12006 281 202.
Stamped on the end of the axel was KW 4360.
The number 3896839 with a 1 or I under the 6 is raised on the pumpkin housing on the front passenger side. There is a GM84 marking on the front driver side.
There is a date code looks to be 8Z1 ? Looks to be a GM Corporate 12-Bolt. I have no clue of the year. I need to fix the brakes, especially the parking brakes. Looks like the cables for the park brakes are all wrong for a K10. Probably came off of a C10.
Thanks for the help.

[kingburnett]

Well, it has been a week and no input from the message board so I put the rear of the truck up on jack stands and spun the rear wheels. They went in opposite directions. I then removed the rear cover and definitely not a posi. Stampings include 3817778 GM 11:41 (3.73 ratio) 2-7 (maybe date) and a 07752 (no clue what that means). I'm guessing that the year range for the 12-bolt truck rear end is a range from around 1964 or 5 to about 1972 or so would indicate that the date is probably Feb. 1967. This unit probably came off of a c10 but it does not have the panhard bolt hole in the top. Added photos to the bucket.

[tooslo60]

I had an 86 k10 that had those same shock mounts. I really couldn't tell you much more about it though, I swapped them out for 1 ton dually axles.

[Captainfab]

The GM truck 12 bolt was used in the K series trucks from '63-'80, and in the C series trucks from '63-'82. With the absense of the panhard bar mounting boss, I would say it is from a K series. In about '76 GM upgraded the brakes to 2.5" wide shoes, so yours is older than that. The self adjusting brakes didn't come out until the '66 model year. So that narrows it down to between '66 and '76. I don't know just what parts you are looking for, but about 90% of the parts for all truck 12 bolts are interchangeable.

[kingburnett]

Thanks for the responses. The reason for trying to identify the year is to try to get e-brake cables to fit. I'm especially concerned about the end fitting stop that is inside the drums. Additionally, the partial cables currently attached look like the short jacketed C10 type. The K10 type have a much longer shielded jacket that reaches up to the frame. Also it seems that there are offset lugs maybe for control arms or something.