I will be surprised if you can use your original column. It looks like there is no bearing at the base of your column which would not be out of line since it went straight into the box. This will allow your shaft to move around making for play in the wheel. With the close ratio rack it could prove dangerous. You will understand this when you drive the truck. The rack takes so little movement of the wheel to turn the truck that any play in the steering connection is amplified compared to the old box. It is taking shape. You are not going to believe how much better your truck drives when you get this finished.