i have a vacuum question?

[13lazer]

i have read all i could about determining how well a motor runs based on measuring manifold vacuum. i am running a vacuum gauge in my dash and it never goes above 14psi and drops as low as 0psi during acceleration. however, it is a well tuned and maintained motor that nobody but me has touched since it was built. its a mild performance built stroker with 264/270 split duration cam and a set of kick ass world products .194/.150 heads. everything i've read says vacuum should read between 17psi and 20psi all the time. am i missing something or is this normal for a streetable performance motor? it seems like my vacuum advance would be affected but i haven't noticed anything, nor do i have any brake booster problems. i normally drive at sea level if that matters? according to what i've read about diagnosing the condition of my engine with a vacuum gauge; my valves are worn or i need a bigger carb. i really don't think i have either prob. my carb is a 670 street avenger and i'm not burning much oil if any? i know there are some experts on this subject around here, i'd appreciate some opinions.