Nice Jeep! I am a new member so I am a bit late to this thread but I am hoping maybe I can offer something useful anyway. I also made the jump to a much larger tire size on my rig last fall. Granted mine is not a jeep but I faced the same questions as you. My rig came factory with 4.10 gearing and 33" tires. My first change was to 35" tires and after a recalibration to the ECM for tire size I seen very little difference in performance on or off pavement. The transmission did have a tendency to downshift a bit more on steep grades at higher speeds as you noted with yours. I did not feel a need to re-gear the truck with the 35's and overall performance was still much better than expected. A few months later I made the jump to 37" tires. After the recalibration for the new tire size the truck still performed decently but I could definitely notice a lack of power compared to before and the transmission worked extremely hard on steep grades constantly searching for the right gear. Off pavement the performance was still great it just required a bit more skinny pedal. This led to me doing a re-gear. I have re-geared a few of my previous vehicles without doing my homework first and this was a mistake. Either I had a vehicle that was a total beast off road but was redlined all the time on the pavement or was great on the pavement and a dog on the trail. I plan on keeping this rig for a long time so I wanted to set it up right to meet my needs and intended use. There is lots of advice out there that will tell you the magic gear ratio for you. The reality is getting it where you want it. I travel a great deal with my rig averaging around 2000 miles a month or better so going deep on the gears was not a good option for the amount of highway time I see. However I wanted to have a bit more grunt off road as well. Obviously to return everything to a final ratio that matched stock was a good starting point. This calculated out to a 4.56 ratio for my truck, however like I said I also wanted a bit more grunt off road and have considered going to a 40" tire down the road. My final choice was to go 4.88 gearing. I run about 180 RPM over what it did stock at highway speed in top gear but the truck does not shift as often on the highway anymore. I went through a lot of online gear calculators but found Filthy Motorsports (new member so I cant post links yet) has one of the better 4x4 calculators out there for gearing, tire size etc. As far as suspension I am a firm believer that there is no "one size fits all" kit out there. Terraflex seems to be a great suspension on the Jeep and I have quite a few friends who are running Terraflex and love it. The one thing I have seen with my own vehicles and all of my fellow off roading friends is eventually they find something they don't like about any suspension they have and end up making changes over time. Those changes can be a simple as a different valving profile on a shock to custom spring rates. I guess my final advice after this rambling post is don't just take anyone's advice. Do your own research and homework along with talking to others as to what works and what doesn't. Putting off a mod for awhile can be a huge dollar savings in the long run VS. trying something right away and finding out later you hate it and have to do it all over. It looks like your on your way already to building the rig you want and it looks great.
