I just finished my KH small bolt patteren set up for my 68 dart. It aint cheep!
I noticed you have a 73 pitman arm and a 68 to 72 Idler arm. you will need to change one or the other.
Oldmanmopar.... your were right. I grabbed a late model steering box off the shelf, cleaned it, painted it and as it turns out my 68 box is still on the shelf! F me!