Here are the two coils next to each other. The ZJ coil, static, without any weight on it is about 21⁄2 inches taller than the TJ coil. Otherwise the dimensions are very similar, with the top uppermost coil slightly smaller than the rest of the spring’s coils on both. Our Rubicon Express budget-boost shocks are long enough to allow the springs to be changed without unbolting the shocks. We did, however, have to disconnect the drag link from our passenger-side TeraFlex high-steer knuckle (“Shrink Ray TJ: Part 1,” Nov. ’12). If your TJ is more stock, you may have to disconnect your sway bar, the lower shock mounts, and possibly one end of the track bar to swap front coils.