Hellwig 78-87 GM G-Body 2dr (Excl. El Camino) Frame FX KitOne of the most effective ways to improve the stiffness and handling of GM A G Body is to box the factory chassis. This process could take considerable time with measuring, cutting and fitting steel panels, however Hellwig Products is making the task easy and even more effective with its custom fit Frame FX kit. This Part Fits: Year Make Model Submodel 1980 1981 Buick Century Base 1978 1979,1982 1987 Buick Century Custom 1980 1981,1984 Buick Century