In working with the engineers at Penske, we’ve developed the ultimate shock for the early vintage competition Mustang. This is a single adjustable aluminum bodied gas shock with no external reservoir. These shocks can be adjusted externally and can be rebuilt or custom valved for your specific application. The nitrogen charge can be checked with a special gauge available separately. Minor spring rate changes can be made by increasing or decreasing the pressure. Specify year when ordering. NOTE: SOME MODIFICATIONS REQUIRED.