If the guides were done early in the engine's life, you are probably OK. If it starts to burn a little more oil, you could just install some new valve guide seals and get another 20-30k miles.

I have seen engines with less than 60k miles that needed a valve job.

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Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS