I agree; AT LEAST 4.88. I have 33's and 4.88, and I need to downshift to 4th if there is a head wind or if I go up an overpass. I really liked the performance of the 4.88 and the 31's I had before, so I would say 5.13 (IIRC that is the next step for a D44) would be ideal for 33's, but you can only go up to 4.88 with the stock axles.