where can you buy pinion shims or a pinion shim assortment? the ones i got in my richmond kit arent what i need. i got the td pinion measuring kit and i need 0.862 on the pinion. and with a .039 shim i get 0.864 measurement, so i figure with a .037 shim will get me the 0.862 measurement. i dont know if the 2thousanths will hurt my rear but i dont know what the plus or minus that is acceptable.

You could try it with that shim and see what the pattern looks like, apparently sometimes the required shim does vary from what the tool says.

For what its worth I just set up a set of used GM gears and the pinion seemed like it was .002" or so too deep, but with .012 of backlash they run completely silent.

i went to a local gm dealer that still had them and they just borrowed me their assortment and did not charge me for what i needed.