seems that alot of 3rd gen love there 4;56 with stock 275/60/20's . any reason why the 4th gen would be any diff? about to get new gears on my 2011. anyone have exp with 4.56 on 4th gen stock wheels and tires? what about the 4.10's? anyone ?

 

I am sure you have seen websites that show what effect gear/tire diameter changes will have on engine RPM. Then figure out which trans gear is closest to this and drive around for a day to see if you can live with it. So what I am saying is put your trans on 3 (for example) and drive around for a while...do you like it?

Go to this website, at the bottom is a gear/tire diameter chart.

http://www.superlift.com/library/gears.asp

 

I have yukon 4.56 in an 06 FX4 supercab on 33" BFG AT KO's and I think it is way too much gear for any daily driving. Need 35" or 37" tires but only did a 'poor mans' lift - 2" spacer on top of front coils and a 1.5" add-a-leaf for the back. I would have done 4.10's if I could do it again, based on no desire to put a lift kit and bigger tires on.