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 lbin Rear 124 - 159 lbin. 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.