So with your tundra and either a stock 18" rim or aftermarket rim with 6.14" backspace the tire I'd run is a 285/75R18 which is available in the popular Toyo AT2 and a couple others. It's essentially a 34.5"x11.5 and fits like a glove. Extra inch of clearance under the diff, still relatively narrow, and large enough diameter to go over holes instead of getting stuck in them, plus it's not a super heavy tire and has a 50k mileage warranty. Depending on where you're taking it big trucks can often use extra clearance, as smaller vehicles can often go around what full sizes must go over. Getting ready to begin a full size build again myself, don't want to be restricted to graded fire roads like my last trick with 31"-32" training wheels. All depends where you want to take it, remember too that what is an easy road in might get washed out with a rain overnight and now it's going to beat the snot out of your truck on the way out. It's happened when you decide to camp away from everyone in the paved campgrounds, but that's why I typically build better than the mall terrain crowd.