We've never been to Mid Ohio with a 206, but. I assume you'll be running the CIK 206 class? If that's the case, get a 21T driver and start with a 58 rear gear. We have found that with a 21 tooth driver and a 57 thru 60 rear, you'll pretty much have most tracks covered.
Speed wise, they'll be in the 64-68 MPH range on most straights in a draft. At VIR, at the bottom of the down hill leading onto the front straight, in a drafting pack of 7, all of us on the limiter, the calculation was 71 MPH. I think you'd have to drop them off a building to go any faster
Clark Gaynor Sr.
At Gateway we saw 71mph in a draft. I think the low 70's is all a 206 with CIK bodywork will do because of the rev limiter.
We see about 93mph at Mid Ohio in the Sprint Enduro Animal class.
A 2.65 to 2.80 ratio should be close for most tracks. I think I had a 2.65 or 2.68 ratio at Gateway.