King pin inclination, or more accuratly, steering axis inclination, is the relation between the Camber angle and the spindle, with Camber being the inward lean and SIA being the outward. The dimension between the two is the Included angle. SIA is non-adjustable. If it is out of spec, that indicates a bent spindle. They should be the same on each side, withing no more than .5 degree difference.
