OK, I know what the effect of oversized tires on a veichel without changing gears, that is why I am asking this.

My truck currently has the 225/70/14 tires. I am too cheep to buy new rims but new tires maybe. What is the biggest tire size I can fit under this thing with these 14" rims?

I got bad news, I had the same problem with my 14's, and I went to see if there was another bigger tire that would fit on my 14's, and there isn't. If you want to get a bigger tire you will have to get at least a 15 inch rim. If money is hard to come by, look on ebay or got to discount tire and by some black 15x8's for 30.00-50.00 a piece. Sorry man.

Matt