The first generation of stock cars used a strictly-stock body and frame, the doors were strapped with the use of seat belts being required, and a heavy-duty rear axle was mandated to stop the cars from rolling over during a race.

[2] These cars were almost identical to their road-going counterparts, albeit with tuning and modifications to the car itself being prohibited.

It was also notable for being the only generation of stock cars to use real doors.

[3] Examples include the Hudson Hornet, Oldsmobile Rocket 88, Ford Galaxie, Plymouth Belvedere, Pontiac Catalina, and the Chevrolet Impala.

They were eventually replaced by the Generation 2 cars in 1967.