I have read the associated threads and scoured the internet looking for information...I referenced JTIS and while I was successful at replacing my upper and lower ball joints there are some aspects of the task that were not disclosed anywhere (at least I was unaware).

I am sharing this information to better prepare fellow Jaguar Forum DIY'ers.
Lower Ball Joint Purchase Lesson's Learned:
1) Most if not all internet parts stores offering just the ball joint by MOOG, URO, Beck Arnley and Mevotech are mislabeled applications. They are for 2002 or earlier S-types. I purchased a set out of stubbornness and confirmed that they were incorrect. Note: The local Jaguar dealership disclosed that one could buy just the ball joint using a Lincoln LS ball joint but that it was not recommended.
2) Upper link arms also have mislabeled applications. A visual indicator that it is incorrect is to look at the location of the ball joint's threaded stem if it is pointing away from the vertical link (aka lower control arm). The stem should be pointing in the same direction of the arm. Jaguar part numbers are C2C25789 anc C2C25788. I opted to go with the dealership to avoid getting shipped the wrong part. Paid $316.80 per arm
Lower and Upper Ball Joint Installation Lesson's Learned:
1) To press the ball joint out of the lower control arm assembly purchase a Pitman Arm Separator (Napa Auto Parts #7769067). Cost was $14.99, a like item is also sold at Advanced Auto. You will also need a rounded file to remove about 1/8" from each side of the gap on the separator. The theory is that as the stem screws down on the ball joint's threaded stem it pushes the ball joint out of the lower control arm. You need to ensure that the gap is wide enough so that the ball joint passes through.
2) The vertical link does not come with the brake splash shield so take a cold chisel to the three rivets and knock off the heads of the rivets. It is recommended to do this when the vertical link is still mounted on the car. I used 1/4" locknut and bolt combinations to replace the rivets. I am perplexed why Jaguar/Ford decided to rivet this splash shield on but it is not that big of a deal
3) With the ball joint out of the lower control arm you will now need to get the ball joint bushing off the older ball joint. It is a tapered fit so you have a couple of options. Apply outward force with your Pitman Arm Separator modified with steel shims (I used steel washers) and hit the bushing with a torch and it will pop right off. If you do not have a torch than you can use a hydraulic press. Remove the rubber boot under protecting the ball of the joint. Cut just under the ball joint bushing. Now take the detached bushing put on a socket and press the remaining ball joint threaded stem off of the bushing. Now you can use the bushing to re-install your new vertical link assembly with ball joint back on your lower control arm assembly. If you do not recover your bushing the dealership will try to sell you the entire lower control arm assembly with like $300 plus dollars. They do not just sell the bushing which is BS.
4) Make sure you have a T-60 bit for your ratchet. I recommend a 1/2" drive. You will need this to remove the strut to get the upper ball joint's out

Everything else you need to know is on other threads and available on JTIS.

If you have questions or want to see pictures let me know. Maybe I did not search the threads enough but in hindsight I wish I would have known about these details before undertaking this project. My pain is your gain. At a minimum you won't have to make several individual runs to parts stores which delays completion.

Lastly I will add that a repair shop quoted me $3200 to replace both sides of my upper and lower ball joints; doing it myself came out to about $900 ...Good Luck tooling

 

Good info, thanks!

So front upper ball joints are not serviceable, and require complete control arm replacement?

The front lower ball joints are serviceable, by way of pressing them in and out of the lower control arms. Which ball joints did you end up going with? The Lincoln LS ones, or OEM jaguar?

 

I ended up going with OEM's for upper and lower.

While I contemplated doing just the lower ball joint swap outs, in the end I opted to replace the entire vertical link which included a new ball joint. If I knew what I know now I might have did just the lower ball joints. A two hour project turned into a multi-day one and I needed to get my car back in operation.