think about this,most all center sections use taper bearings for the pinion and carrier loads,hence tons stronger. the green ball has a lower side strength than taper,period. IF you doubt,put one in a press,and try and push the center out.boom
...then try a taper.
.if they work ok for some,cool. but the way the 8.75 is designed,the taper was used for a reason. would you put rollers in the front spindle of your auto/x car? nope,the ball would push through the side walls of the bearings...
. i would agree that a minimal load,drag/street would be ok for a green,but i wouldnt want to chance a failure for the little work of setting proper axle end play on a taper,myself.