I'd be surprised if they weren't all from the same manufacturer, whether you bought from Mike's, Erik's, Boyce, Eastern, Memphis, etc.
If you drive your truck alot, and don't want to continuously re-do the slot seal,
DO NOT use the little POS cork to fill the tab slots on the rear spindles. I custom cut pieces of old rubber valve cover gasket with a leather strip cutter that tightly fit in the slots, install them with a bit of RTV in the slot itself, and trim the rubber fillers about 1/16" long so they'll mash into the slot more when the spindle nut is tightened. Before you put the outer seal on, with the outer bearing installed, clean the outer face of the bearing and the inside of the outer seal where it contacts said bearing, apply a very small bead of RTV around the circumference of the spindle where it meets the bearing, THEN install the seal, put another very small bead of RTV around the circumference of the outer seal where it meets the spindle, then go about putting on the nuts/tab washer, and setting the play. Be advised, the flat plate of the outer seals are very soft steel. If you crank too hard on the initial torque to "set" the bearings, you may shear the slot tab off of the outer seal regardles of whether it's lubed or not (IMHO, 50lbs. is plenty). All this may sound like overkill, gotta ask yourself... how much would you "enjoy" tearing down, re-packing and re-sealing inside of a year or two?