The Jeep JK Stage 4 Synergy long-arm suspension system by Poly Performance was engineered from the ground up to allow the JK Wrangler to work better than the sum of its parts. It includes everything needed, including front track bar relocation bracket, drag link flip kit, rear track bar relocation bracket, and upper and lower long control arms that are adjustable while on the vehicle. Once you remove the stock frame bracketry from the JK and drill a few holes, the Synergy system is completely bolt-on. We chose to go with 3 inches of lift and the progressively wound coil springs looked too long out of the box. They’re not. Synergy coils are designed so they stay seated, even at full axle droop.