I had a similar issue when replacing axle bearings, etc., in a junkyard E body 8 3/4. One axle would not go all the way in. In my case, the issue wasn't the axle housing, it was that the bearing wasn't fully pressed onto the axle. Put it back on the shop press and started pumping. Got to where with all my muscle I could barely move the handle and the bearing wasn't moving at all. I was wondering if I was gonna tear something up when - finally - with a loud "POP" it went all the way on. Then the axle went into the rear w/o a problem.
I was thinking the same thing as you - this job shouldn't be this hard. On the other hand, it seems these days like nothing is ever as easy as I think it's gonna be. :mad: