what the clutch bell numbers from that last post b/c the internal gear ratio is very different from a vlx so you might look at it this way with a 32 pitch cb you will see about 10mph top speed increase by changing your clutch bell froma 15 to say an 18. I put a 24/56 on my rc10gt and it would take 4 runways to hit top speed it's geard so high... i used a 19/58 or i think to hit 55 mph and it got there fast. if your racing over a 100 feet or less go with a bigger spur gear or smaller clutchbell to get more excelleration and top your car out real fast.