74 Duster, resto mod 6.4 front end rebuild questions

In process of gathering all my suspension bolts etc to take to the plater to get them zink plated etc. And whatever items need to go to powder coaters like lower arms etc. Have a whole PST front end rebuild kit and thought ill get the upper arms ready to powder coat so can get the bushes in and back on car.
The threads looked funny and yep, removing the upper balljoint has cooked the threads, needed a 6ft bar extension to undo them.
Tried a new upper bush in and just drops through the thread.
Not sure if thats a common thing to happen undoing a upper bush
See in the pic that the threads have lost their teeth. Think ill just get new Dr Diff pressed ones as the engineer isnt a fan of tubular as they are not rated and have mixed reviews from people in the know

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