The Porterbuilt Fully Adjustable Trailing Arm Crossmember is designed to eliminate multiple rear suspension concerns that are presented when lowering the rear of a 1963-1972 truck. It is a direct bolt-in. It also allows for multiple fore-aft mounting points. The advantage of the multiple fore-aft mounting points is to allow the wheels to be centered in the rear wheel well opening with various drops. It is available for two piece driveshaft configurations and will allow for a 3" exhaust.