Check the width of the frame, it could be made fit. The thing is, you wouldn't gain much with the Caprice frame, shure it's newer and would handle better, on the caprice at least, you have to figure that the caprice body is a lot lighter than a '55 Chevy body. With the modifications you would need to do to the '55 Floor and floor braces to make the '55 body fit, shure it would handle a little better but not much. My suggestion is price the components to make the '55 frame handle better, the parts are available and probably cheaper/ less the hassle than fitting the caprice body on. another problem you want to think about is, you would have to modify the frame horns to fit the front bumper. And the car with the original '55 Frame will be worth more.