8 3/4 swapped in but....thrust button?

^^^ WHAT THIS GUY SAID^^^ On any nonstock narrowed axle, I recommend green type bearings for a reason some don't consider. Besides the reason that it makes finished axle length much less of a PITA to deal with, ball bearings generally have a better go of dealing with any misalignment issues that the housing may have if an end is just a little out of true. You should see what a bent axle housing will do to ride on type axle bearings and shafts. A friend wishing me well picked up an 8.8 Ford with custom Dutchman axles that was in a 1000 hp Third Gen Hemi powered 1974 Duster. It had pretzeled the axle tubes and they ran it until the toe out out on the rear got nearly unmanageable. (I imagine it was howling like a banshee, too!). That is one set of brinelled axles. It took a lot of 48 ounce ball peen and 6 pound sledge hammer action to get that one apart...