I was wondering if 33 12.50 is bigger than 285 70? I am thinking about buying the 33's but I want to make sure they will be a little bit bigger. I do have a 3" leveling kit and a add a leaf so bigger shouldnt be a problem. Also will 33 12.50 17 fit on my 2005 stock 17" wheels without causing problems? Thanks.

 

285/70/17 is actually 33x11.5. 33x12.5 will fit but thats as wide as you can go on the stock 7.5 inch wide rim, they are not taller but they are wider. There will be no problems running that size.

 

The width is normally the issue, with an aggressive sidewall you run the risk of scrubbing your upper control arm at full lock with a 12.5" or 315 width.

I'm assuming your trucks 2wd (if it's 4x you can do 35s), the 285 should be a good fit, you may want to try a 295/70 to get a tad larger than a 33x11.50

 

I know a couple of guys who run 325/60/18's with no problem, they do however run aftermarket rims with backspacing that sticks them out a bit. However I still dont think 12.5 will be a problem

 

Depending on the sidewall and the truck (seems random) the 12.50s rub the upper control arm in some cases when installed on the stock rim.