never used the 360s and they will probably do well with mostly plastic or a light tank on flat ground. My experience with my Bulldog (metal tracks, metal sprockets, steel 4:1 gearboxes) has been that the Speed400s didn't get me to scale speeds and they lacked the torque for climbing or running through a lawn that needs mowing. Also, all that metal in the backend caused the front end to stick up. I had to fix that with about 1/2 lbs of fishing weights. All said and done, the 480s with a 14-tooth pinion gave scale speed and excellent torque. Put a fan on your RX-18 if you don't already have one.