Blank tie rod adjusting sleeves
So your rack and pinion has an M14-2.0 threaded shaft and you need a female outer tie rod end to go from that to the stock steering arm on the lower ball joint?
Like this?
Just a thought, but the steering arm doesn’t care about the UNF thread. It just needs a 7° taper and somewhat close start and stop diameters. 9/16” is ~14.2 mm, so a tie rod end with a m14 thread and a 7° taper would still probably seat, and I imagine a tie rod end with both metric dimensions would be easier to find.
Your other option would be a heim conversion using a tapered tie rod adapter. These are used with bump steer correction kits. In this case the “pinto” version has a 9/16” thread and 7° taper like the Mopar parts…
Adjustable Tie-Rod Adapter Stud to Heim
Then you’d just need an m14-2.0 heim with the right end bore, or even one that could use a sleeve to match the adapter stud.