[suicideneil]

31/68?!?

What setup are you running that requires such a massive pinion ( tires, motor kv, voltage etc )? Running 1/8 diffs does tend to mean you need a pinion with about 3-4 extra teeth in order to get the same ratio as when running stock diffs, so it may not be an option unless you can alter the rest of your setup to improve things a bit...