May not have been original to the truck? Sorry but I can't find that number anywhere or any sequence even close to it in my notes.
Have you felt or looked up on top of the tube on the passenger side? The rear I'm using came from a 1969 Chevy 1/2 ton and was stamped up there. I had to look around to find it, actually. I think the axle codes for the 12 bolt break down like this:
B, W, G or K tells you where it was produced (K which shows up in your number might mean it was built by McKinnon or it may mean it was built in November...can't uscramble that egg) B means Buffalo, W for Warren and G for Chevy Gear & Axle
A through L tells you the month it was produced (A for January, L for December) if it was made between 1964 and 1970. If your rear end was made after 1971, 01 for January through 12 for December.
If it was for a 69 or 70 truck, it will have a panhard bar ear cast into it. This will be on the passenger side. You can see this below.
The gear ratio codes are always two letters or one letter followed by one number. I'm not going to post all of them because it is a long list, but you can probably find them online somewhere. I will tell you if yours is a 3.73, my notes say it will either be CC, CI (if it is positrac) or also could have been CU (for posi), K4 or K5 (positrac). That's all the id codes used for 3.73. I've never seen any 12 bolt which didn't follow this ID sequence, but that's not to say one didn't happen somewhere. Good luck.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
