It used to be stock car meant one thing. But guys streched the rules. Created what was a modified jig car. No stock frame but just a tubular chassis and a thin sheet of metal. In the late seventies they added a wedge nose. Most use a 75-85 chop block Chevy Malibu engine with a hand made back end. Brakes, tires and suspension are chosen for the track. About 30 thousand dollars in each car.