QA1 R220-250 Rear Coilover System 65-72 F100 Double Adjustable 250lb/in. SpringsQA1 R220 250 Rear Coilover System 65 72 F100 Double Adjustable 250lb in. Springs For the rear of 65 72 F 100s, QA1 engineered a unique torque arm design that maximizes performance without the inherent binding issues of other systems, all while achieving a 4" to 7" drop. This bolt in system also offers unprecedented adjustability: the panhard bar, torque arm, trailing arms, bracket mounts, and shocks are all adjustable, and they are truly independent