One piece 1957 chevrolet frames are not california frames
The one piece frames that Chevrolet made in 1957 for the passenger cars are not California frames. They are just supplied from a different Chevrolet plant. Many1957 Chevrolet cars built in the Oakland CA plant do not have one piece frames. Same goes for the Los Angeles plant. One piece bumper's are a California thing, in case of a crash, they needed to separate the cars fast and the one piece bumper's allows the car's not to get tangled together in the event of a crash. Domenic