I have 315/70 18 (35.5”x12.4/18)on my overland with the 3.73 gears. It runs fine on road and fine off road for moderate trails. Still gets me 18mpg if I don’t get on it and does 75+ just fine.
My dealer told me 4.10 were the most they could do. They state anything other would void warranty. However they did recommend an outside shop to do it. I’ve been told by a shop here in town $1700 parts and labor.