You don't need to order anything.
Just jam in the new upper ball joint until it's seated, and tack weld it in, as mentioned.
I'm not a fan of it but it does work, very well.
Fyi those are "lower" ball joint thread inserts linked earlier. I'm not even sure how that's possible. But I wouldn't buy em if they can't call it the right thing or have designed a thing to fix a non issue