Hotchkis Sport Suspension 1917 64-66 GM A-Body Lowering Coil Springs Set (4) 1 in. Drop (Big Block). Lower your Chevelle El Camino GTO or other 64-66 GM A-Body car with Hotchkis Sport Suspension lowering coil springs. These springs will lower your vehicle on average 1 in. from factory ride height enhancing vehicle looks while lowering the center of gravity. The increased spring rates offer improved performance and handling while offering a comfortable ride. Each gray powder coated coil spring is precision wound using the highest quality steel. Specs: 1 in. Lowered Front 580 lb/in Rear 124-159 lb/in. Motor: Big Block. (Big Block cars using aluminum heads or many Pontiac Motors such as the 400 should use the small block spring 1900). Note: Wagons and El Camino's should not use rear springs without the use of 31750 air bag kit.