Correct, It sits inside the frame just like the pictured box, It has the same mounting holes as the 78 monte carlo style box, and the Factory YJ box, however the pittman arm on the astro box comes off the front of the box. This does mean that the box operates in reverse compared to a YJ stock box, that way when you input steering to the left, the tires still turn left.
If you just flip the pittman arm on a standard YJ box then,
left=right, and right = left. This combination would work, but you would then need to mount the drag link behind the axle.
This is why I went to the Astro box. Mounting holes are the same, input shaft is the same, and the lines are the same as a stock yj box. The astro box just allows the front stretch and still keep mechanical steering linkage. Also, the astro box allows you to still use standard Saginaw box modifications.
