Axle won't go in far enough

I am assembling my 8 3/4 rearend after taking it apart to replace a broken wheel stud. Since I had it apart I decided to replace wheel seals and bearings (old rearend out of a parts car). I painted the rear end and puchased new gaskets (steel and foam) and I am putting in a 3.91 sure grip 3rd member. I put in the divider before I installed the 3rd member. I installed the LH axle with no problem. When trying to install the RH axle feels like it's going in the splines but not far enough. There isn't enough threads showing to even start a nut on the studs. I have played with my axle adjustment with no success.

Any help would be appreciated. I usually call my dad for issues like this but he is a Chevy guy and has never messed with this type of rearend.