Differential rebuild
Gears manufacturer: Yukon Gears
Ratio: 3.42 for a series 2 - 10 bolts GM carrier
Supplier: http://txdrivetrain.com
Suggested backlash: 0.006 - 0.010"
Set backlash: 0.008"
Contact patterns during 1st installation (0.010" backlash)

Stock shim + 0.004" was too noisy so I reopened the rear end 100 miles later...
Contact patterns after 100 miles (0.008" backlash)

After removing the additional shim the rear end became 100% quite!