Looks like a 60 but check the bom, if it's from a 79 van it should be a small bearing ff 60. Do yourself a favor and take a visit to your local pull a part junkyard and pull a 60 from a late 90's early 2000's ford e350. They're cheap and plentiful, they'll net you bigger bearings and can be found with 4.10's, if your lucky you may find one that doesn't need a full rebuild right off the bat. No matter what axle you have layin there, if it's been sittin for more than a few months, I'd go through the whole thing before I ran it.
