Looking to upgrade from the stock Chevy tires (265/65/18) to a more rugged look. Thinking about getting the KO2 in size 285/70/18. I measured the wheel well side to side and it looks like they will fit fine but wanted to ask and see if anyone has this size on their truck and if so, can you send a picture? I don't want to have to trim anything nor have them rubbing

 

Just be aware that your speedometer and over time your odometer will be off if you go that direction. I went from 245/70R17 to 265/65R17 on my 2006 Silverado after doing the math to make sure that by increasing width and decreasing sidewall height ratio would result in almost the same tire circumference. I basically did it because no-one local had the 245/70R17 in stock.

Here is a calculator that can help in comparing tire circumference, which is what will screw with your speedometer/odometer:

Tire Diameter And Circumference Calculator

You really want to stay within a few percent of the original tire on the circumference. And be careful going too wide, so that you don't hit the inside of the front wheel well when making sharp turns.

 

Here is an even better calculator, that will show the effect on your speedometer:

https://tiresize.com/speedometer-calibration/

Looks like your change would have your speedometer reading 65 when you are actually going 70. I.e. you would be doing 5mph faster than you think you are, and your odometer is racking up fewer miles than you are really traveling.