QA1 now has GM Pro Coil Systems available for your 1963-1965 Buick Riviera. They offer fully adjustable ride height and valving control. Pick your spring rate and adjustability to fit your driving style, adjust the valving to match and you are on your way. They 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. Specially designed for QA1's Pro Coil Systems, the American-made lightweight high travel springs have fewer coils and a smaller wire diameter, resulting in increased travel due to the larger distance between the coils. They reduce unsprung weight and react faster, optimizing suspension performance. Multiple spring rate options are also available and have been successfully tested in various applications, from casual street driving to hard core race applications. Adjustable Pro Coil System Features: Available in independent compression and rebound double adjustable and simultaneous compression and rebound adjustable Lightweight Billet Aluminum Coil-Over Shocks High Travel Springs Easy, Bolt-In Installation Ride Height Adjustable 100% Dyno Tested and Serialized Serviceable and Rebuildable by QA1 Authorized Service Centers Made in the USA Used in drag racing, street performance, autocross, road racing and street rod applications Sold in Pairs.