The spacer on the left is adding preload by reducing the space available for the spring, not by adding weight. Because of this, the weight of the vehicle will compress the spring to the same length with or without the spacer. The preload is cancelled out because the spacer doesn't add any...
When the spacer is on top of the spring, the entire spring is move down away from the body. Either way, the distance from the control arm to the mounting surface of the frame is the same.
The illustration is shown under vehicle weight. Before installing, they would all be the same length.
The length of the spring under load remains the same no matter where the spacer goes.
Placing a spacer under the spring extends the shock, moving the control arm further from the body.
Placing a spacer above the spring extends the shock, moving the control arm further from the body.
If the...
Still have it. No marks. Sensors are easy to get to. unlike the Mod bumper. Sensor rings are intact. Comes with Ford license plate bracket, if you want it.