How much space between flanges and shaft ends on a 9"?

I am getting back around to unpacking all my stuff that I had in storage while in flight school. The Ford 9" I pulled has me in a bit of a situation though. It is a big bearing housing that I pulled from under a '69 F-100 or something along those lines. It measures 57" from flange to flange. and the ends are a 1/2" bolt on a 2.3x3.5 rectangle. I see the distange from seal flange to WMS seems to vary with application tough. It looks like this could turn out to be a 62" WMS axle after I am done with it, which would be nice. The local yard has another out there which they list online as 4wd so I need to go pull it's D44 brother for the front.

So:
Is anyone running this particular axle, from this series truck? If so, is mine factory correct, or modified and moved from some other application? Searching on the internet yeilds about 6.9 billion different results, all of which look like they could be correct. It just seems like mine is too narrow to have come from that truck.

I have perches, the housing, and a nice large bearing 3rd member ready for assembly. I just need to hammer down the specifices of the axle so I can order shafts, a locker, and a bearing seal kit.