I'm using usa standard gears in the rear, which are said to be a lower tier than Yukon. They are fine. Noise isn't bad, honestly pretty much the same as the factory gear noise. My pattern could be better, but I haven't had time to pull it apart and re-do it. The rears were 250 or 350 cad (dont remember). Rears super common. I believe Yukon sells the front gears based on when I was looking. Also a wrecking yard in Alberta has the complete 4.10 rear axle if anyone is looking. I ordered the front from them and just used the factory set up and swapped it in. I did install a torsen lsd in the front and a clutch lsd in the rear.