38s without a gear change?

I currently have a 6.5 inch lift on 33s I want to add 38s 37s. I have a lunchbox locker in the rear. Has anyone added bigger tires without changing out the gears in the diffs? Anyone’s experience doing so?

I currently have a 6.5 inch lift on 33s I want to add 38s 37s. I have a lunchbox locker in the rear. Has anyone added bigger tires without changing out the gears in the diffs? Anyone’s experience doing so?