Hotchkis Sport Suspension 1922 1994-1996 Impala SS Sport Coil Springs. When we decided to manufacture coil spring for the Impala we took our time and researched other springs on the market. With those springs in mind we found a great combination of performance and ride characteristics. Our springs feature a progressive rate design and come complete with urethane spring pads and bump stops. Specs: Impala SS 1.25 in. Front 1 in. Rear. 90-96 Caprice 1.5 in. Front 1.25 in. Rear.