Most likely a traction bar will be required with any spring over kit. If you find springs stiff enough to prevent axle wrap they will be too stiff to give good flex. The stock springs might work pretty good here. They already support the weight of an Xterra rear end, are relatively flat and would give decent flex in a spring over. Add a traction bar and wrap is no longer a problem.

Here's the first photo I found of what should work.


You weld it to the pumpkin or axle tube and attach the shackle end to a crossmember up front. One is all that's needed. A shackle at the forward attachment point is important to let the suspension still flex. If it's just a pivot you'll kill flex because the traction bar and leaf springs will triangulate the suspension forcing it to one position. It may be possible to use the bolts for the "third member" to do a bolt on bracket at the diff, but I would rather weld it to the axle tube further outboard to keep from interfering with the drive shaft.