Every aftermarket 489 case I have assembled, set up with around 0.038" (+ - 0.005) pinion depth shims.

BTW, there are only 2 sources for new 489 castings and neither is Moser. Are you working on a black powder-coated casting? If so, I recommend checking the oil galleys carefully, as they are usually packed with casting sand.

I would start with a 0.038" shim.