Looking for help installing Spicer front axel on CJ3A

I'm in the middle of a frame-off restoration of my CJ3A. When I pulled the front axles, both were Rzeppa but the left joint came apart in my hand. I ordered a new axle from Kaiser and received a Spicer, which is a "standard" U-joint like you find on a drive shaft. I was told they were interchangeable. The joint will not fit through outer opening of the knuckle and arm as does the Rzeppa, so I fit the axle into the axle housing before I installed the Knuckle and king-pins. The Spicer axle should free float in the differential just like the Rzeppa. My problem now is that when I install and torque the spindle, the axle is in hard-contact with the bronze spindle bushing that I installed. The replacement bushing has a flange on it that the old one didn't. In any case, the spindle bushing and axle are pressed so hard together that the axle will not turn. As well, the axle is pushed so far into the differential that there is no float. Has anyone used the Spicer replacement axle with the replacement bushing w/flange with success. I hate to go milling on the spindle bushing and/or cutting on the axle if I have made a bumb mistake somewhere else. Any thoughts?
stoney