AMA Superbike rules for 2K4

Here are some snippets on the rules this year: Must be production based street use for sale in U.S. Maximum 1000cc & 370lb minimum with fuel Only "Lightly" modded stock crankshafts are allowed Stock gear ratios and one AMA-aproved set of alternate Limited mods to the stock frame (for strength) Four-cylinder must retain stock throttle bodies and airboxes Twins can use stock throttle body plus one alternate & can use aftermarket airboxes