Those interested in such a class would do well to use the PA Super Sportsman class as a model. The only part of their program that wouldn't work in Indiana is the chassis. They require square tubing in the cockpit area while you would need a basic sprint car chassis here in the Hoosier state. Other than that their rules are exactly what you are looking for. 355 engines with flat top pistons and many other restrictive rules to keep the costs down. The class has been around for decades and has always put on excellent racing. At their former home track in Carlisle, PA (Silver Spring Speedway - now closed) they averaged over 50 cars every Saturday for years. Contact Alan Kreitzer at Williams Grove Speedway for more details.