[glen]

Valves should be adjusted every 100K miles as the valve gap tends to tighten ,so say Detroit.

[Archived]

See my thread on it HERE

Should be done before 100K, and it is a must do in my book…smoother running, better mpg and things set where they should be. All my clearances and injector heights were off.

EDIT: would also add to change out the valve cover gasket for a new one, I reused mine and its started to leak a bit so next week i am replacing it with a new one.