I would try 100k in the center, the truck seems to rotate very well naturally. You always have some throttle to make it do what you want if 100k is a little thick off throttle.
I want one of those trucks bad, don't hate but mine will have the 28.5cc reed motor in it though, I've seen a couple videos and that motor is nutty. The thing keeping me from getting one is no track for 1/5th around me to run it at.