You did in fact ask a mechanic,thus the reason for my answer. You can get all
kinds of numbers,knowing what to do with them is another matter.Adjusting
valves involves a good bit of auto savvy. Done wrong it involves a good bit
of money. Sometimes it's best left to a pro. Which you may very well be.
I didn't read your profile.
If your hood is original , the specs will be on a label on it. Don't do the adjustments yourself unless your experienced.Improper adjustment can lead to many other problems. It's okay for them to make a little noise , especially when cold.
ONE MORE TIP...a little loose is better than a little tight. To tight will give you that quiet sound you probably want , but can also lead to valves not closing completely. If you have a simple vacuum guage take a reading of manifold vacuum, warmed up , at idle , before and after the adjustments.If adjustment was an issue then you should see a slight improvement in the reading. good is 18-20" needle should be STEADY. If it fluctuates rapidly then you've got a valve problem. good luck.