The strut body is inserted into a close fitting socket in the wheel hub and the pinch bolt pulls the socket in tight against the strut housing. If the strut can pivot on the lower end and the wheel hub has another pivot point, there would be nothing to control the camber throughout the wheel travel.
One thing I forgot to mention about the inexpensive spark checkers: If you have one or more that appear to indicate irregular spark, switch it with another and observe if the problem child follows the spark tester. The way the ignition system works, if you lose one spark plug, the other one of the pair is likely compromised as well.
Here are instructions for making the test light I used. Reatta Owners Journal - How To Make A CPS Tester Some people have found that a digital volt meter would work for doing the test but mine wouldn't. That is the reason I had to make a test light.
You can do the tests on the old ICM but the tests were intended to be done on a car that won't start. I was hoping you still had the Delphi ICM to use for the tests.
I did the tests on my car when it was running fine just to get a baseline on what the test results should be. You should get the same results I did if you do the test. I don't think it will help with pinpointing a miss or poor performance if the engine will start and run.