Backlash and Pinion depth question?

This depends, if the case you have already has a set of gears in it with a good set up then it's simply a matter of removing the pinion shim in the current set up and adjusting it for the new gear. The measurements are on the head of the pinion gear. For example one set may say 2.245 and the other set may say 2.242. This means the 2.242 set needs to be .003 less deep into the ring gear so you would simply subtract .003 from the shim used in the 2.245 set to arrive at the 2.242 installed depth. And don't think for a minute that .002 won't make a difference, it can.

Now if you have an empty case or perhaps a new aluminum one from MP or something like that then you either have to have the special tools to check and set the pinion depth or it's trial and error which means assembling and adjusting, disassembling and reassembling many times. Don't ask me how I know.

Either way if someone has the tools and knowledge to use them then I'd say $150 is a fair price. Or if someone doesn't have the tools but knows how to do it by trial and error (some tools are still required, like a press) then that is probably worth the money too.

Oh and this doesn't even touch pinion bearing preload, crush sleeves or the proper way to set carrier bearing preload and backlash.