The tab on the adapter rests on top of the frame and acts as the vertical locator. In most cases, a power-steering box will need to be all the way forward, against the back of the front bumper. This vehicle has custom framerails now, so the box is positioned so that the drag link is parallel to the tie rod when the pitman arm is in the middle of its travel. Clamp the box in place and check its position. Then weld the adapter to the framerail.