Why is my manifold vacuum so low?

The OP sounds like one of those guys that pays for everything to be done, learns a few "car guy" terms but has a hard time understanding them. This could explain why he cannot understand or answer the basic questions.
Diamond Springs is below 1700 ft above sea level, I live about 30 minutes from there.
Bill: If you want help, don't be a dick to people that take the time to TRY to help.
Sure, sometimes you'll get responses that are NOT helpful but you get what you PAY for right? Everyone is a volunteer here...Nobody is paid to help you out.
If someone asks you to check this or that, they are doing so because it may reveal the cause of your problem.
* Initial timing has a great effect on idle vacuum. Check it.
* Drilled throttle plates lower the vacuum. Answer the question ....Are yours drilled?
* Did you degree the cam? Camshafts that are not in their optimal position will negatively effect performance.
I recall the words of a wise man I once knew. He didn't like to be bothered for stupid ****. He would often say..."Help me help you. This meant ....Don't make me do everything for you.