1970 c10 2wd - manual to power steering ??

[c10327]

I have a 1970 c10 that came with manual steering an having an issue with pit man arms ? the manual Pittman arm wouldn't fit the new power steering box as the splines shaft was different . so I bought a power steering pit arm an it fits the new box but now were it bolts to the drag link the shaft is different size than the old manual shaft . the shaft is a little to small to tighten up properly ? do the make a shim or is the another pit arm for this kinda swap ?? any help would be great