On my first KR(white one) I ran it with 35 inch tires and 3.73 gears with no issues. 22 inch rims and tires are really heavy.. The trucks are made to move a lot of weight. I only tow my 4wheeler.

My second KR(Black) is a beast as well.. No tuner nothing... One thing though..... My truck is VERY picky with gas... I only use BP and never skip a beat... When I use a 7/11 or mom and pops gas station I end up with loss of power and pinging from the water dew build up..

 

I always used quality fuels and high on maintenance on my old truck so that isn't the case with me. The old truck was just chitting out I suppose. I did have my fun with it, and some have said the 04/05 trannys are crap to the 06+ ones. I'll just hope this nice '07 is healthy and won't beat on it.