D44-F250 unusal date code?

[Lars-S]

Greetings all.. I recently came across a Dana 44 front axle out of an F250.. It appears to be a 78'.
Took a while to find stampings on short side (driver) as paint had filled them in.
I've been using the Dana/Spicer info from the books ending in 78 and the one beginning in 79 plus the listings of all the BOM's on this site.

It is a : 610040 - 4 ?R?

Its strange as though I can find the BOM listed when I go to miscellaneous small parts that BOM doesn't show .. it shows 610010 then jumps to 610047 and 48..

That seems to indicate its from a 1978 F250.. The really odd part, ok my lack of knowledge, is the stamping to the left of it doesn't to me match the format shown in the spicer identification section .. So instead of X XX XXX (date) it has this:

I searched a lot and found it might be julian day and year, as in 83 day of 77, but B doesn't seem to be a location found and 4 isn't a shift that I ever heard of. Still the BOM suggests 78 so that kind of doesn't make sense to me either.

HELP?
Thanks.

 

[Snoranger]

https://www.therangerstation.com/tech_library/pdf_documents/Dana-44_1967-1978.pdf

 

[Lars-S]

That is what I used to find .. assume it is a 78 F250 axle .. thanks..
I am curious though about the weird date code stamping .. which should match that??
And from that same manual X510-9 pages 67 and 68 show the small parts for 610010, 610047, 610048 but nothing about the 610040 ??

thanks