My rear D60 has the stamp facing rearward and between the right brake plate and the spring ubolt. It is just a bit below the tube centerline.
The front D60 also a bit below horizontal centerline and 5-6" from the center housing toward the passenger side, and facing forward. These numbers match the diff tag if original.

 

Rear D60

Front D60

 

Sorry, guys. My house sold so moving and all that jazz has taken up all the time. I finally found the VIN on the frame after a lot of searching. I haven't gotten to the axle yet but I wanted to get this posted so I can start ordering chassis parts since it needs a lot of maintenance items (bushings, brakes, engine/trans mount, etc.) The VIN is X36SKFA2016. Off the top of my head I know that's a 4x4 one-ton chassis. I'll have to decode the rest later tonight when I get a few minutes to just sit and have a beer. I know this doesn't help much with the axle identification but I'll get back to that search as soon as I can.

EDIT: Number found of front, left side of front axle - 8 14 8 C5 610040 4

 

It looks just like my 79 axle. I just did all new brakes front and rear. Rotors, pads, studs, axle u joints, wheel.seals and bearings. The bom number on mine was on the front driver side of the axle I found it with a wire wheel be carefull not to go to crazy you could rub it off. Also for the axle type on the opposite side of where you have the c383? Number there should be the axle number mine is and is stamped 44-9f. Sourced all the parts locally. If replacing calipers i was told autozones manufacturer does not know when then will have more. Orielys had them in stock about 60 a piece plus 50 core and the are bracketed

 

I wish I had seen this when you posted it. Thank you and sorry I didn't respond to this earlier.

Great info, thank you. I'll have to look for another stamping.

 

'79 was the first year Ford made an F350 Supercab in 4-wheel drive. The beginning of your VIN, X36SK is the same as mine, which proves that it's a 1979 Supercab (X) F350 (3) 4-wheel drive (6). The S denotes it has a 400 engine, and the K denotes it was built in Kansas City. Your truck is a '79, not a '77 (except for the grille & headlights). Your front axle should be a Dana 60. Maybe a previous owner cobbled this truck together with parts from other trucks?

 

BOM # 610040-4
Ford ID # D8TA-AGC
Dana Mod# 44-9F
4.09 Ratio non-locking w/ free running hubs
3,800 lb. capacity.

 

I was about to reply with another view of a BOM but I just noticed you found yours and Mike deciphered it for you.

Additional links that may be helpful to you or others in the future:

Ford model 44 front axles, Bill of material table

Dana 60 BOM table

 

In case I missed it, tell the NAPA guy you have a 79 F-250 with 3500 pound axle. That will get you right parts

I am building a Frankenstein Jr., and you just have to tell the parts guys what they want to hear...

 

The VIN your referring to is on the frame rail. The body is a '77 as per the door jamb tags. I knew this before I bought the truck. The nice thing is that someone along the line threw a 4wd chassis under it instead of hacking the front off. Definitely the route I would've gone if I were to do it.

It has an unknown 460 in it. I don't believe it's from a dentside but perhaps a car of the period because the front crossmember near the harmonic balancer is hacked to hell. Judging by the appearance of the frame relative to the rest of the chassis, it seems that someone replaced the chassis as a whole instead of throwing a frame under it with whatever other suspension and axles could be found.

Fantasic, thank you.

Thank you. I'll check out those two links on my lunch break tomorrow.

It's odd, Napa's system doesn't seem to do well for a '77 F350 so for the usual maintenance things I've been telling them it's a '79 F250. The wheel bearings is where I came to a halt with the axle question, which is why I started this thread. I didn't want to get the wrong ones, tear into it, have to return them, and not have the truck until the following weekend when I could get what would hopefully be the correct ones (they have to order any of them from their warehouse hub.) Thanks to Mike and Maddog I've got that info now, and thanks to you for the heads-up.

EDIT: Also, cbrown, something funny I just noticed from your signature: I've got a dentside and you have a bumpside. I've got a '94 GT and you've got a '96 Cobra. And I've got an '08 Escape (current winter use) and you've got a '13 Escape.