You're going to have to get some calipers(or use a tape measure) and a thread pitch gauge and measure the thread pitch and the diameter of the threads.
Once you know that information, then you can look up what ball joints are available with that diameter and thread pitch.
The ones that I used are a 7/8"-14. That means the diameter is 7/8', and the thread pitch is 14 threads per inch.
Measure what you've got on the Jeep, and then look for corresponding TRE's.
These ones from Trail Forged are 7/8"-18. So maybe that what you need. They come in different thread pitches. Remember too, that there will be a right hand and left hand thread on the TRE's. You need one right, and one left hand thread TRE's in order to properly set the toe in. Make sure you have one of each and they are in the right orientation.
Apex Chassis Tie Rod End, GM 1 Ton, Offset Right Handed
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