Eventually you'll need both tires and gears. I'd probably get the tires before I'd get the gears (been there done that). It may not be a pleasant drive with bigger tires and no gears, but it ain't impossible. Heck, I was on 4:10's and 35's, 4:30's and 35's, 3:31's and 35's, 5:71's and 35's. You're gonna feel the difference, and you may not like it, but I don't see what it'd hurt