Keep in mind a 1 tooth jump in front is roughly equal to 4 teeth out back. Gearing will be dependent on the longest strait, slowest corners, and driver weight. If there are several tight turns you might have to gear so you are on the limiter a bunch on the long strait. Won’t hurt the engine to do that. You will just need to get in the ball park and test from there. You might even need to change gearing as the track changes throughout the race day. If you can find the high mph of a LO206 at your track, you can use a speed calculator found online to get you pretty close. They are base off your gear ratio, rear tire circumference, and the max rpm of the engine (6100).