Lifter failure

The FT lifter problem started mid-late 90s, so lifters made before then should be ok.
It's possible it was before that, but we'll likely never know. I well remember Lunati having problems with flat cams in the mid to late 80s. They replaced a lot of cams around here under warranty. I knew some guys at a local Chevy oriented machine shop and Lunati is what they ran exclusively at the time. Their failure rate was something on the order of over 75% of what they sold at the time.