489 pinion bearing install?

I agree with what ph says. I've built countless 8 3/4's and I find rears that have shims behind the cone to be done for ease and I don't think the factory ever did this. On a used R & P the most important pattern is on the coast side of the gear set. Your looking for a mesh pattern in the center of the tooth as possible. But Hell sometimes no matter how hard you try some set ups are going to whine.