The only thing im sure of is that your 1/2 ton axels more than likely wouldnt last very long. I have 35x13.5r18s on my silverado and I blew a rear end after about 15k miles. I tow on ocasion (maybe once a month, dual axel trailer) so that would have contributed a little bit. You would probly be alright with a re-gear, im not sure.