Wheats the largest mud terrain tyre I can fit to a standard vehicle?
215/75/R15 MTs will fit on a standard Samurai, although if the springs are sagging or the anti-roll bar is removed, they may just catch the top of the wheel arch on full articulation. Tyres larger than this will require a suspension/body lift and maybe the front bumper mounts trimming/removing and the wheel arch seem flattening by the bulkhead.