PART NUMBER: F30. Radius Arm Suspension System w. 6" Lift & Hydraulic Shocks for 11-16 Ford F250/F350. 11-16 Ford F250 4WD. Increased ground clearance and better looks than a radius arm drop system. To avoid stacking rear blocks or going too tall with a single block, Zone includes a 5" cast iron block with an integrated bump stop as well as dual add-a-leafs.