8 3/4 rear end confusion

Hello guys, I was re-doing the brakes on my 1973 roadrunner with a 340 and I ended up doing the inner axle seals as well. As you guys know, the axles have to come out and I was in the process of putting the driver's side axle back but it will not seat completely. I have done some research and believe that I have a sure grip dif and that there are 2 sets of splines in a sure grip. I also did not replace the bearing with the "green bearing", it is the original one that I kept and lubed up. I feel the axle go into the first set of splines but then it won't go in any further. The studs just barely begin to go through their respective holes on the axle end so it doesn't need to go in much further. When I go to spin the axle, I can't spin it by hand even though the rear end is off the ground. The trans is auto. What should I try first? I know that sure grips are tough to spin in general but would it help to put the trans in neutral? Should I put a pry bar in between the studs with a couple of the lug nuts on and attempt to spin the axle slightly while applying force inwards? One more thing, the passenger side axle is off. Should I try to put that one back in first or will it not make a difference? I appreciate everyone's help!