As Y-Tim said. 215/75R15 is the largest tire that will fit a stock Samurai. With a 1.5-2" lift, e.g. OME springs in my case, 235/75R15 will fit. You might look into pounding flat the fender seams inside the fenders -- they can easily cut a tire. The 215's will fit a stock Samurai wheel. Larger tires are usually specified for use on wider wheels, but a lot of guys mount them on stock wheels anyway, without apparent problems.