You are correct. This is what I have been saying all along. My misunderstanding is at fault in believing that I should be measuring from the head surface and not the top of the bottom base or shim.

I now grasp that what I should have for the installed spring height is the actual compressed length of the spring itself, after it has been squozen between the upper retainer and the lower base or shim, not from the head to the bottom of the retainer. Spring height is in a sense a misnomer which confused me.

Therefore my spring pressures may be higher than recommended if my original measurements are correct, which remains somewhat uncertain subject to how well I have visualized the spring's position at its actual contact point at the shrouded upper retainer lower surface. This .060 could increase pressures substantially, I have not a clue as to by how much until I can measure them.

Without the specified tool as your photo of John's spring height measurement illustrates, this appears to be a bit problematic for me.

I believe however if I remove a regular valve spring and replace with a ' test' spring this will be simpler in obtaining a correct measurement using a caliper. I do not understand the purpose of a test lifter(however which I do have) in obtaining this spring height measurement. Unless possibly your concern is rocker arm retainer contact in the event that installed height must be corrected.

Tomorrow if the ordered valve spring tester should arrive, I will measure spring pressures.
I would have this question: If all pressures remain within CC's specifications and no coils are binding(which they are not) and no rocker/retainer contact is noted,,,are all systems go regardless if installed heights are shy by your .060 thousandths figure? My theory being with springs no longer new, they likely have already lost 10 to 20 percent of initial pressures.

This has been a learning experience for me in an area of engine technology(cams and valve trains specifically) where I suspect very few outside of the industry understand slightly and fewer still understand well. I suspect there are on this forum of those who may not have become too bored with this thread and are still following our exchanges and particularly your commentary have learned as much as I have on this topic of "when things go wrong in your valve train and why they did and how do you fix it".

As a fellow Moparts forum member traveler stated to me earlier this evening, this shines a light onto and exposes a previous little dark corner of the Mopar world.