Can't seem to see the pic you posted.

 

Linkee no workee.

Some 9's have an 8.7" ring gear, but everything else is the same.

9 inch ~ Mid-year 1969: FoMoCo changed the differential bearings (4221) & cups (4222) to a "Slim Line" design, then used 'em thru 1986 (see pic in post 11).

Since all the bearings & cups have BIN's stamped on them, buying from autoparts stores is EZ as these are the Bearing Industry Numbers also used by bearing shops.

Some 1974/79 9's have a ball type axle bearing, some have a tapered roller bearing/seal combination.

The ONLY way to find out which is which, is by pulling an axle and taking a look-see.

 

Sorry, I am computer challenged. Just did a google image search and found this:

https://www.google.com/search?q=ford...tm%3B380%3B363

The two middle pics in the top row show the curved rib.

 

Green53, the dana 44 is popular with 4x4 guys. Any parts vendor will have parts for it, including mail order places like summit and jegs.

 

Hopper, ever change gears on an integral diff, not near as easy as a drop out style, heck even pulling axles is a pain with the C-clips, plus not as safe if you break an axle. That is why the Ford 9 is still number one, parts all day, fairly light, and strong.