[factorystock]

Don't know who designed it, but, more of why it was designed, a smoother ride. First appeared on 1960 2wd 1/2 and 3/4 ton pickups, but 1 tons continued to use leaf springs for heavier duty work. The coil system you see on 67-72 Chevy pickups is basically the same system that was introduced in '63 ( see photo ).