* Springs are rated for Diesel engines only. Gas engine models will realize slightly more lift.* Will not work on models with manual transmission.* Pinch weld on 2005-10 Super Duty radius arms may come in contact with radius arm drop bracket hardware.* 2008-16 models with gas engines may need exhaust modified to clear front driveshaft.* Rear add-a-leaf may be required for truck to sit level when using 6" block included in kit.* Models with a 2-piece rear drive shaft should order carrier bearing shim kit.* No driveshaft modification needed.