How to decipher Steering box date codes?

[Mr70]

The shift & line codes I denoted with a letter there,mainly to differentiate it apart from the rest of the code.I haven't come across any P/S gear boxes or hoses yet that had a letter there...so far.
But I have found letters used to denote the shift & line on the side of steering columns & P/S reservoirs from the years 1969 + up.

[mockingbird812]

little help here with date decipher?....



Thanks!

[Mr70]

That Manual box shows a casting date of May 19th,1969.

Look on that machined boss at the 7 O'clock position to the top cover for the assembly date.

[mockingbird812]

Thanks Rick. I see the julian date i.e. 139 = 19 May, but what is the indication that it was cast in 1969. Is it the "9" above the part # on the case? This box came out of a 06A built '69 Malibu.