There are many classes at BNI/SCTA events. You could run a 100cc go kart and set a class record. You have to analyze the classes and engine breaks and determine which one can get you to a class record. Getting the largest displacement for a class helps get the required power. You want to get the biggest engine you can, you will be running against the big dogs in the unlimited class. That is where you find Speed Demon with 2500HP LS engines. You need deeeep pockets to play there.