Hot bodies 1/8 diffs

[cmac]

I'm putting together one of my hybrid bulks, and I am trying to get the right number of shims. Is it normal to hear any noise from the gears? or should it be completely silent? I am using gorilla snawt on the ring and pinion. I tried it with 2 shims and had some noise. I tried it with 3 shims with more noise. No shims about the same amount of noise. 1 shim seems to be the best, but i can't get it completely silent.