From what I've read and if I'm understanding things correctly, they check the cam specs at the rocker arm and it has to be no more than 1% of the stock lift and duration can't be more than 2%. The class is called pure stock muscle car drag racing and the rules are pretty strict. It's a class set up for factory performance cars. The car you run had to have a 4 barrel carburetor as a option from the factory or you can't compete.