Sounds like you're on the right track. 16 is a tad low, but not bad. For one thing, you have a new and tight engine. Have you changed the oil yet? 500 miles is time. If you don't have ready access to break-in oil, go with a 10W-30. Here's a good page for basic info.
Century Performance Go to tuning and vacuum gauge, it will tell you how to diagnose things like valves out of adjustment. They're not that hard to adjust, either.
