Extended Notes: 1. Strut compressor required for installation. 2. Requires frame bracket modification and welding. 3. 18" wheels with 5-5.5" total backspacing should be test fir prior to mounting tire to ensure proper clearance to BDS steering knuckle. 4. 18" or larger diameter wheels required. Stock 17" & 18" wheels cannot be reinstalled. Stock 20" wheels can be used with up to a 305/60-20 tires. 5. E-brake bracket required for factory powersteps (123018) Block kits replace factory 1-1/4" block. 6. For a level to tail low appearance use #023415 with Kit#598H or use #013429 with Kit#573H. 7. Models with a 2-piece rear driveshaft may require carrier bearing drop shim kit #123402 8. Will fit EcoBoost models. 9. This kit is FMVSS No.126 Compliant The NHTSA's Federal Motor Vehicle Safety Standard (FMVSS) No.126 requires all new passenger vehicles to include Electronic Stability Control (ESC) systems that meet certain standards that can be tested through a comprehensive series of evasive maneuvers. Aftermarket products must meet these standards as well. BDS Suspension is leading the industry by independently testing all suspension kits to verify our kits are fully compliant with the stability control system requirements set by Federal Motor Vehicle Safety Standard (FMVSS) No. 126.