Complex sentence: Similar in layout to the frame adopted for the 1957 Cadillac, it featured box-section side rails and a boxed front cross member that bowed under the engine, these "x-frames" were used on other 1958 to 1964 Chevys, as well as Cadillac.
Split into simpler sentences: Similar in layout to the frame adopted for the 1957 Cadillac, it featured box-section side rails and a boxed front cross member that bowed under the engine. These "x-frames" were used on other 1958 to 1964 Chevys, as well as Cadillac.