Adamo, as you might know already, they are very very different and there is no way to make the 57 Chevy metal work in those two area's. 1955 Chev rockers are concave the way the 57 Pontiac rockers are, so i wonder if there is a way to make the 55 Chev rockers work. That is a question for the C.P. brotherhood out there. Good luck.