QA1 Pro Coil Systems for 2003 - 2011 Crown Victorias are a great option for anyone looking for fully adjustable ride height and valving control. Choose a spring rate and adjustability that fits your driving style, adjust the valving to match, and you are on your way. These shocks also utilize a fully threaded body that allows you to adjust your ride height for the perfect stance or to finely tune the weight balance for superior handling.