I sure hope someone from track answers your question because without knowing the radius of the turns, or if there is banking. and how much, it's pretty hard, it seems to me, to give any kind of gearing recommendation. 17 60 is 3.51. Seems to me that's a big gear for that size track. Still, I don't really know so maybe I should just stay out of it.
I just hope someone from the track we're talking about can give you good advice.
Comments compliments criticisms and suggestions are always welcome.