New JK owner here! Been reading up on the necessary gear ratios for my setup. I have a 2010 Sahara 4 door unlimited. 3.21 gear with 4 inch lift and 35 inch tires. I'm not complaining too much on performance because I am comparing to my 97 wrangler and that thing was sluggish. I mostly drive highway miles and it does become sluggish around 65-75 mph. My big question is if I stay at 3.21 does that do any damage to the vehicle or is this mostly a change needed to improve performance and gas mileage? If I do decide to go for it, anyone know of a great place in the Philadelphia area? Cost? Which ratio? I am thinking 4.1. Thanks!