Do both sides bind, or just one side? With the axle out of the jeep,if you just slide the spindle over the axle, does the spindle spin freely? Does swapping the spindles left to right help?
I guess first I would carefully measure the old axle and the new, overall and also the inner and outer shafts.
Are the shouldered bushings fully seated in the spindles?
I was going to replace mine also so I'm very interested to see how you resolve this....