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Re: i have a vacuum question?
Not to worry.. you are probably OK.
First- Confirm your factory guage is 100% right on, if you want. Steady needle a little low by your 30 year old guage, nothing to worry about. It should climb higher as your engine revs, mirroring your tach, on gradual acceleration. I am thinking stuck needle, because if your engine never pulled over 14 inches, your vaccum idle, it would never rev upbeyobd an idle.
B- Dropping to zero then climbing back up is normal. That is why you have power valves and pump squirters on your carb. They "cover" the lack of vacuum during a quick wide open throttle event.
III.- Split duration cam and a 670 might be hurting the vacuum a tad. SOunds like you have plenty of vacuum, as your booster works properly.
Tuning by vacuum is more of what the needle does, than the initial reading. I ran one in a drag car, as my hearing is whacked in the " loose valve" range. A well placed and accurate VAC guage is better than a tach, and can tell you when you need to break out the tool box.
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