I personaly wouldn't go lower than 5.29's in the diffs cause of strength and according to the marlin chart that setup up would yeld a crawl ratio of about 221.1 with a 5spd and they say that is ideal. I am running dual cases with stock gears and 5.29's and that puts me at 110.1. I can see were a little bit lower would be nice with the 4 banger, but not often. I run bolth cases in low and 2nd gear through most of the rubicon