Like Kissalien said..These guys for the most part are very open with some of thier mods. They woint tell you everything, but most will give you help, on your car, if you ask. They run on bias ply tires. They were never speed rated as far as I know, but they've gone over 130 IIRC on a Corvette. In regard to how strict they can be, my dart Swinger is not legal, because of the color, and the aftermarket sun roof I have. Yet I could restamp a larger carb if it's visually similar, and hied wiring for a variety of electronis, and be totally legal if I wanted to paint a '71 color on it. They allow K&N elements, but in factory air boxes. The fastest ones are not really street cars. They look stock, but they are scienced out to accelerate as fast as possible. Hemis IIRC are well past 480 cubes now, and I think 700-800hp. That Corvette ran a 10.95 when I was there. Very cool cars, and very nice group of guys. But a little rough in the rules department for my taste.