Not every gasser had a straight axle. A car was a gasser or modified production as soon as you put an engine in it that wasn't available in it from the factory. I started out as classes for street cars, not the all out race prepaired pro cars that came in the mid to late 60's. Even then in the slower classes like D on up many were dual use cars. Many of these cars looked almost stock on the outside and went to work every day.