489 Crush sleeve or Eliminator
I have never built an 8 3/4, but have done many GM 7.5 and 8.5,8.6 and have always used 1/2 impact to crush. Once you get the crush started it becomes easier, but you have to be ready to stop, know how to feel the pinion tightness, too much and you start over. I think the torque was 30inch lbs on new pinion bearings, 15inch on old. But the 8 3/4 crush sleeve is really beefy !!! No wonder guys are using eliminators.