[Sid]

As far as your rich condition I wouldn't rule out a power valve problem. One test you can try for a power valve is turn your mixture screws all the way in. If the motor does not stall you may have a bad p.v. Having a backfire can damage a power valve. You may also want to check fuel pressure and float level. As far as the vacuum I think you are in the somewhat ball park with a performance cam. Not knowing what the lobe center line is. A cam with a lobe center line around 108-110 will have a lower vacuum then a cam with 112-116 lobe center line. In a perfect world at sea level and a bone stock engine it wouldn't be unusual to see 19+ in. of vacuum. One thing to watch for is a steady needle. Also elevation plays a small role in engine vacuum. It may drop about 1 lbs. per 1,000 ft. in elevation If it is a fresh engine it may even increase a little after breaking in. Also when using a performance cam you generally run a little more initial timing. I think I would probably go to about 8-10 deg. advance as a starting point with hose off the dist. and tune from that point. Also as mentioned earlier watch valve adjustment.