The Air Lift Spring Spacer Kit will not add ride height to your truck, and should only be used if you add a rear block or add-a-leaf kit. Only a rear block or add-a-leaf kit will add rear ride height to your truck. Whether you'll need either a block (or what particular size) or add-a-leaf will really depend on how much rear ride height and rake you want to get back after the Fox installation. We haven't tried installing a 4WD coilover kit on a 2WD truck, so we're not sure exactly how much front ride height you'll end up with.