When you install a leveling kit the toe is the main setting affected, you will definitely have uneven tire wear without an alignment. On my '10, that had 500 miles on it when I installed my 2 in level, the shop told me the toe was way off and caster on one side was slightly off. Now I'm not saying every truck will be off like mine was, but if you want your tires to last an alignment needs to be accomplished.