It’s not much, on the setup bearings I have made it has been from .0005 to .0015 I’ve had to hone out. Not much at all. Just a nice slip fit. I did the ones for the 79s 12 bolt on the Sunnen hone, the ones for my friends 14b sf I did with a hillbilly hone. Some folks like to use the old pinion bearings as setups, with the ones I’ve built the old bearings were bad enough I think it would have been a wasted effort. Note that while the ID/ODs of bearings and races are close tolerances, the overall length is typically a little more open, like ten or fifteen thousandths tolerances on the lengths, so two timken bearings may have a different overall/installed height, which will effect the setup. There is a way to check the delta with a race, the two bearings, and a test indicator. Once that delta is known then it’s easy to compensate for it.
A good bench stone (that’s flat), small granite surface plate (or heavy glass, granite countertop) and some emery cloth sheet for checking/knocking burrs off is good to have. Does not take much to introduce error into measurements due to a burr or high spot.
I like to stone or hit with a file any mating surfaces, ring gear to carrier faces mainly, and I personally deburr the ring and pinion teeth with a cratex rubberized abrasive wheel on a rotary tool.
Check the runout of the face of the carrier, check backlash in 3-4 spots, that can provide good indication if the gear set has runout or issues, something not seated right, etc.
Cleanliness is key, clean everything, and then again!
I recommend a clamshell type bearing puller, the ~$120 ones are good units. It will save the bearing if you have to pull it to adjust the shim.
Write down shim combinations and take pictures of each trial setup, with a note of the combination, that way you can revert to one if needed.
That makes sense with your choice of 4.88s, I’m sort of stuck in a mindset between the Cummins and 35s with 3.55 gears (1600rpm @65) and non overdrive stuff.
