The ID and OD are both larger on the wagon bearing, therefore the wagon axle has to be larger in diameter, at least where the bearing goes.  I suppose you could press a sleeve onto the passenger axle to use the larger bearing, or put a sleeve in the housing to use the small bearing.  Ford evidently felt the need for the larger bearing in wagons, Rancheros, and retractables for their perceived heavier loads.  Not sure why they put the large bearing in the T-Bird.  Maybe they expected Bird owners to do a lot of road racing with high cornering speeds.

John - "The Hoosier Hurricane"

Whats the difference? I was thinking that they may use a different bearing but was not aware of an axel difference. What about the T Bird axel? I'm thinking I pirated the wagon axel and used it in my T Bird when I broke one.

You are correct, Skyliner, wagon and Ranchero are the same.

Be aware that the station wagon axle is different from the passenger car axle.  I think the Ranchero axle is the same as the wagon's.  Maybe retractable too.

John - "The Hoosier Hurricane"

Collecting parts for a '57 station wagon 9" housing. Could also use a good set of brake drums.