Help!!! lsd output shaft fitment problem

[One_Beer]

OK, here is what I did. I got a J30 Differential changed out the ring gear with original, and put it in the original pumpkin fits perfect! But now, my J30 longer output shaft won't go all the way in. Is there an alignment problem? Do I have to align something??? The smaller one goes in without any problem. I hammered and step on the longer output shaft but it won't go in. But it comes out easy.

I appreciate any help.:dunno: :help