Wil,
"gear ratios resulting in top speed/distance"
First is top speed is not the ticket,but distance is for a full hr.
Here in Fla, ;
Except for the Fiveflags Speedway race,the tracks so far are about 1/4 to 1/3mile per lap in collage parking lots around the cones and that for the most part holds speed to around 25 to 28 MPH.
So your gear is wheel size and sprockets to try and get what ever motor you've pick to run at it's best rpm for it.
What I'm saying really is all the tracks can be run with pritty much same gear,except I think Fiveflags Speedway could of used a taller gear by a little as I see that the speed looks like it was about 30mph,but then I didn't get to run there,just my guess.