Just remember one thing and we have covered it a bunch of times here its not always the motor that makes someone fast but it helps.
Years ago I did real well in the IMOW class... and was being checked constantly... check the rpm, check the gear ratio, check for open rear axle (back when it was required) check tire pressure, check, check, check...It got old real fast....
Never was anything for them to find, but "rumor was" I was cheating...I was too "new" to being doing good...
Just cause they're winning all the time...don't mean they're cheating...