A tech or competitors can poke around all they want, mic the cams or test compression etc. But without a full tear down you cant catch lighter pistons, lightened rods, flywheels, valve train (anybody know the correct weight of a stock Jensen Healey valve keeper?) Why not use a system like NASA and base the cars on power to weight ratios? ITS say 13.1, ITA at 15.1, etc. Cars could then be adjusted with penalties and breaks for competitiveness. This could go a long way towards keeping costs down. For instance on an Miata, you could spend $1000.00 on machine work blueprinting a motor to get an extra 5hp. If you weren't restricted by rules, a $200.00 cam swap or throttle body would net the same hp. As long as your car isn't over the horsepower for your class, it's fine. Regular dyno certification and no cockpit adjustable engine management is working very well in the NASA American Iron class. America Sedan and AI cars have very similar outputs but you can put together the AI motor for much less money. And a dispute is as easy as a dyno pull.