A- Body (1966-76): Energy Suspension Hyper-Flex System "Master Set" 1966-76 A-Body - Dart, Demon, Duster, Sport, Valiant, Barracuda (thru 69) Features: Quick Off-The-Line Starts Handling Stopping Control Alignment Longevity HYPER-FLEX™ is Energy Suspension's unique and technically advanced chemical formulation performance polyurethane. HYPER-FLEX™ has been used on Energy's products that have been awarded 9 U.S. Patents. Durability is superior to most rubber components that are used for cars, trucks and SUVs. Road salt, oil, and a host of other common under car contaminants will eventually destroy the rubber bushings on your vehicles, not to mention the weight and torque forces that typically compress most rubber permanently! HYPER-FLEX™ replacement polyurethane components stand up well to contaminants that often destroy rubber and have been engineered to give longer-lasting performance and not compress permanently. HYPER-FLEX™ is offered in a variety of durometers (firmness or softness), depending on the a particular product application. Performance tested and race proven, it's used for all of our products that require a higher level of performance and durability! We call it "The Cure!" If you are modifying, building a new vehicle for scratch or restoring an old one, Energy Suspension's HYPER-FLEX™ performance polyurethane should be the "ground zero" focus of your present and next vehicle plans. Does not fit 4X4 models.