I need some help what is the biggest tire I can go with the stock rims with a 2.5 level any help thanks

 

18" rim and 4x4?

If so you can go up to a 35x12.50. Depending on what tire it is you may have some minor rubbing.

I am running a set of 295/70/18 Nitto Trail Grapplers. They have a pretty aggressive sidewall and I have NO rubbing. If you find a tire you like that is offered in that size I think its a great option. It measures ~34.6 x 11.7. See profile for pics. Let me know if you need more info.