I ordered the coil spring conversion kit for our Mark VII. In less than 4 hours using a floor jack and railroad ties to sit the car on. I had completed the installation of all for springs. In the driveway. No special tools and no problems. Everything fit in place perfectly as advertised. The springs lift the car higher than the air suspension did, and the ride is much better. The car handles better also. No more problems from the suspension, air, warning lights, nothing.