Hi Terry,
For your sake I hope Ford wasn't blowin' smoke
If you do have a problem, Ford will happily let you pay for it
The problem with the prior springs was a combination of high lift (over 0.7" at the valves IIRC) and triple springs. This combo had a fairly low fatigue life. Plenty for a bunch of 1/4 mile runs, but nowhere near enough for a "daily" driver.
At around 3-5K miles users reported they started breaking. Not good.
I have one of the earlier engines that I paid Ford and others a lot of extra money to beta test - $2800 extra to be exact. Ford din't help any at all
I didn't have the valve spring problem (whew!) because I wanted a hydraulic roller setup with lower lift & higher durability and coincidentally, double springs to replace the triples. It's working fine at >8K miles!
Now if I could learn to keep it right side up...
Tom