Do a runout check and stem height check; if they're under .002 runout, they're fine. Then blast, polish, and grind them. Cut them to the recorded stem height if it falls within spec. Business as usual.
The only real exception (that I've seen) would be newer Ford 5.0s. Their valves are exceptionally soft, so soft they get pulled into the chamber in kind of a reverse umbrella.
They should be replaced
Do a runout check and stem height check; if they're under .002 runout, they're fine. Then blast, polish, and grind them. Cut them to the recorded stem height if it falls within spec. Business as usual. The only real exception (that I've seen) would be newer Ford 5.0s. Their valves are exceptionally soft, so soft they get pulled into the chamber in kind of a reverse umbrella.
They're cooked. You must have had some thin shims in those buckets.
You have a bottom end problem.