on d35 for example a shim kit is between 0.144'' to 0.174'' with shims in increments of 0.002'' - these go between the bearing cup and the housing. You are limited of course to .144 minimum shim thickness unless you make a custom one. you cannot use a combination of 3 or 4 shims to make let's say .130 total as the caps are not covering the area close to the axle tube, so those could walk out and possibly cause the bearing cup to become crooked and wedged sideways in the housing.
the Superior are placed in the same location and have a lot of thin ones, however they have a centering shoulder so you can use thin shims for final adjustment and they are held in place and centered with on that shoulder. The master shims are also machined all around compared to the stock ones which are only faced, doesn't really matter but i was impressed with the quality for the price. I'll take some pics and post them.
with the regular D35 shims you need to put the thinner ones between the thicker shim and the bearing race so it's covered by the caps - i personally don't have too many shims (i did buy a set of stock spicer shims but the thinest one is too thick for me) so this was a nice and cheap find to solve my problem. In your case you can probably make a thinner shim from the ones you have on your lathe if you have a toolpost grinder (you probably do), but these are a good solution if you don't have access to any of these shop tools/machinery not to mention the time would take to make a custom one.
I will probably end up using one side on the D35 (and save the other for the D30) and machine a custom thin one once i have the final thickness (so i can drive it in and not spread the case for preload).
like i said, i'll post some pics to compare
