What year is the K5 that you're selling?
I'm on my 2nd JK Rubicon (both 2 doors, you know, a real Jeep LOL). My '09 was a 6sp. and had 15" wheels and 33's. I had no complaints at all with the 3.8. Now I have a '14 automatic and 35's with the stock 4.10 gears. I see no reason at all to regear and the engine has plenty of power. I hope that the 3.6 Pentastar holds up because I plan to keep this one for a long time.