P-Case 3789812 decoding
 

I got this years back when my uncle passed and can't figure this thing out.It is some kind of mutt.Casting # is 3789812 which i think is 62-64 only.However the casting date is K16 Nov.1 1966 i think.Scrubbed to look for the code but does't seem to have been stamped on the opposite side.Doesn't look to be posi anymore Ring gear is 3733908 9-37 4 69 for date and pinion 3733912 9-37 and 3 69 for date.So my question is could these all be over the counter parts? Should there be a code stamped still if they were.I know they were hard to see sometimes but I don't think this one got one.Any thoughts of what it might be worth as I think sooner or later I will sell it.Any help would be appreciated Thanks
If someone wants to see pictures I can email them I don't have enough skills to do them here

Yes, that is a service part, both the posi case and the ring & pinion gears.
The 812 cases were the LAST version, which was used during VERY LATE 61-64 production (VERY LATE 61-62 Vettes and -64 pass cars). Since there are no pictures, I can't tell if it has a posi or non-posi differential. The gears are 4.11------------------not a big demand for those anymore. If it does not have a posi unit, then the ONLY thing of significant value is the P case-------------------and that's not worth a whole lot since it was made AFTER regular production as a service part. For just a posi case, it has a fair value, but for the person looking for a correct dated case, 64 was the last time it was used on a production car (62 for Vettes).
If the P case was sold over the counter as just a bare case, then there would NOT be any stamped code on the pass side.

Tom Parsons

Thanks for the reply and info Tom it was very helpful!

I sent you a PM.

Tom Parsons

I emailed you back You must not have recieved it I will try to send again

I finally got it late.

Tom Parsons