Dad, if what you are saying is true, light weight pistons and pins, different cam profiles, tricked up valves, etc. don't make a difference, why write rules against them? If the cylinder head is the only thing making power, why don't they go with a rule against porting the head and leave it at that? If they aren't going to enforce all of the rules, all of the time, what is the sense of writing a bunch of rules? If one guy wins, and I know his car has modified valves or modified pistons, how can I be certain he will be caught? Can I file a protest? If I do file a protest, will they be willing and able to properly check his engine? If he is caught will he be disqualified? Why would anyone build a legal car and go to the track knowing people will cheat and not be punished? If one guy runs illegal engine parts and gets away with it, can the next guy run illegal tires? This whole deal sounds like you can run anything you want as long as it isn't too obvious.