My current set-up is; 4.0L I-6, 5 speed manual, d35- 3.07 rear, d30- 3.07 front, 31″ tires. Currently, I cannot use my 5th gear on the highway, so I would like to re-gear to 4.10 or 4.53. I can’t decide if I should go with 4.10 or 4.53. The max tire size I would have is 33″, and I would like to maintain my current 15 city mpg. Which ratio would be best?