Muncie Mystery Codes/ Gurus needed!
 

I have a 4-speed muncie and where the date code should be I have the number 39116 and where the vin # should be I have a CC1 stamp.
I purchased it connected to a 396/375 from a 69 camaro, I haven't pulled the side cover off yet to verify that it is indeed a M22 as was indicated to me, but I can't find references to the strange date code numbers?
I also have an M20 which clearly shows the correct string of digits so it is not like I don't know what I am looking at...
I've exhausted myself and am now looking for help from a chevy guru!