you're very lucky. us along with a couple other shops in town have all quit using yukon gears for the fact that 4 out of 5 sets whine. pull them out, swap in motives or g2s with the same shimming, and quiet as factory. after i had to replace 5 sets with less than 10 miles on them, i refuse to install them.
Truck: 05 GMC CCSB SLT Z71,
Go Faster: 5.3, 219/227 .607/.614 112, milled heads, eBay CAI, Circle D 2800, 3030 Built 60E, E-Fans, 3030 Tuned, LT's, Spintech Muffler, DuraGrip w/ 3.73's
Look Better: 10K HID's lows & fogs, tinted Chevy tails