Hi I run about 7.03 with my 8.5 speed passion motor which I got by using a 27t pinion and a 76 spur and work from there as you can go up to 6 or down to 8 so that is in the mid of its rang so see how you get on the 76 spur is a kyosho part so its not hard to get but I think you get beter gear raing on it for the 8.5. Hope this helps.
