The UCF Flat-Bottom Coil-Over Tab is laser cut from 1/4" carbon steel plate.  The bolt hole is 1/2" in diameter.  The lower surface is flat to allow for shock mounting to the top of your axle tube with the bolt positioned perpendicular to the tube centerline and as far out as possible while leaving room for the high-steer arm at full articulation.   The distance from the lower surface to the center of the bolt hole is 4".