I am using a 4.09 rear gear. I do have a 6 speed but the 4th gear is a 1.00. Cruising around town is great. With the torque and boost of the motor you can accelerate from 1500rpm to 6000 and cover or break all speed limits. I was contemplating that with keeping the 4 speed and running the dif I am using. But cruising at 3800 rpm to get 70mph would be annoying for long trips.