if you ordered the wavetrac only and plan to install it into your diff here are a thing or wto to look for AS YOU CAN DO IT YOUR SELF.

after the diff is out of the car, and on the bench

HAND TURN THE YOKE GET A FEEL OF IT YOU WILL NEED TO DO THIS AGAIN AFTER INSTALL.

remove the SNAP rings keep left on the left and the right one on the right as the snap rings are the shims.
so now remove the center section, move the ring gear to the wave trac ,, you will have too get new bearings and races,install them
install the center section back into the diff housing,,,install the snap rings, hand turn the yoke, if it feels as it did when you first removed it , your ready to install the rear cover and put it back in the car,

note: the wavetrac is made to be within .007 of the factory unit. so if it is hard to turn take a brass bar and smack one of the the snap rings that will either tighten or loosen it up, then smack the other side it should center everything up and now turn like it did when you removed it. good luck, you really don't need it as this is simple to do. jim