We have been building and selling these kits for several years now, but we have never put them on the website. We start with a Ground Control designed rear lower shock mount. Machined from high carbon steel, and using a grade 8 bolt, this rear lower mount is designed to carry the weight of the car after springs are added to the shock. We utilize a Koni monotube rear shock, adjustable for rebound damping. This shock is available in our standard default damping for standard width cars, or heavier damping for wider cars with higher spring rates. The Koni shock is mounted inverted for less unsprung weight, and features the exclusive GC coilover hardware with single-locking sleeve and your choice of Eibach race spring. The same kit is used to supplement rear torsion bars (PCA Stock Class) or by choosing a different spring rate, the rear torsion bars can be removed completely. If you are considering over 700 pound rear springs, we recommend fabricating a double shear rear lower mount to supplement our lower mount.
924 and early 944 (steel arm) is in development and will be the same price.