FMS gears pimp. I "hammered in" a set of 3.73's reusing everything including crushsleeve and ended up with silent gears that didnt have a spot of wear a year and 1/2 later when uninstalled. You just need to play with the the pinion nut, tighten...take for drive...listen...engine brake....retighten.....repeat till they are silent. Took me 1 tightening to get it right.
I reused my pinion shim when I did my gears - worked fine for me. Conventional wisdom is not to reuse the crush sleeve. Make sure your backlash is within specs and you have a good wear pattern. I did mine for the first time a month a go, and I appear to have nailed it the first time!