Updates the rear suspension camber curve to meet the needs of modern, wide, low-profile radial tires. The result is superior grip in turns, superior grip in straight-line braking, reduced tire wear. Excellent for both street and track.   As the suspension compresses in turns, countering the effects of body roll and matching the needs of modern radial tires. The tire remains square with the road surface and the contact patch is improved. Grip increases. With the ASP ’69-’89 911s can now achieve modern suspension performance.   Replaces the troublesome stock eccentric adjusters with simple double-adjusters. ASP allows adjustment with vehicle weight resting on the tires making it easy to read a camber / toe gauge while turning the adjusters. Quick changes can be made trackside even if a camber gauge is not available.   Replaces stock ’69-’89 spring plate blade and spring plate cover. Bolt on – no welding required, works with torsion bars or coilovers. Use with any standard size bushing – not included – PolyBronze recommended. Requires the splined hub portion from a set of factory adjustable spring plates or the QuickChange Spring Plate splined hub. Download instructions for more information.   Installation Instructions