bigger tires

[bretman38]

hello everyone. ive got a 02 libertywith 225/70/16 i want to put a bigger tire on it(not 38's) :lol: does anyone know anything about something i heard of that goes in the springs. someone said it is polyurethane bushings. i don't want to put a lift kit on it just so i can put 31s on it but i use it up here in the mtns of va and i really need a bigger tire.any help would be appreciated. thanks:shades: bretman38