BY advancing the intake cam you are getting a charge of gas into the cylinder a little quicker, but this runs out on top end, advancing the cams will give you more bottom end tourqe. Now the reason that your off a little on vacuum is that exhaust gasses are pushing some of your intake charge back out into the intake. What I'm looking into is advancing the exhaust cam a little and increasing the intake charge, leaving my intake cam at center as it came from the factory and getting rid of the exhaust gasses more quickly. This is the overlap, where exhaust pushes some of the intake charge back, or holds it up from entering as quickly. This in turn will or should give more vacuum. If you lost 2 lbs by advancing the intake cam, you may gain 2 lbs from advancing the exhaust cam and leaving the intake cam back where you had it before the advance that you adjusted in. More vacuum equalls more signal or throttle responce.
Neat though that you could feel more power on the bottom end, thanks for a good post, I have been wondering for some time about expermenting with these possibilities on cam adjustments for our model cars.
Will try on mine in a few days and will get back with the results.
Poolman