Hello I have a problem with my Chevy engine twin turbo.
I have an LSX block with warhak heads and an original cam and stiffer valve springs.

The problem is that crackles fall off valve
first time it was on an exhaust valve. when the valve stem had been gnawed by the crunch. After that we changed brands. and this time it has an intake valve keepers fallen off.

I lathes 6400rpm max.
and I charge a maximum of 20psi (1200hk 1633nm)
and when this happened I loaded 10 psi (750hk and 1200nm)

What can cause this problem?
it may be rpm stop?
boost pressure?

Jonas Hallenborg