Hi, Everyone:
Sorry for this long post, but I am enjoying an interesting learning experience. I am not an expert, so I thought I would ask the experts for some advice.
Engine had been rebuilt before I bought the car. While it is the original engine, there is a mild cam in the motor. "Normal" engine vacuum has been about 15 inches and there is a slight flutter, I assume from the overlap of the valves. The motor also has the Breakerless SE module in the distributor....
I noticed that the timing was set at what appeared to be about 14 or 16 degrees advanced.
I had no issues, no pre-ignition or run on and no noises that I could hear from the motor at mild or harder acceleration. But, I reset the timing to spec at 10 degrees BTDC and didn't think about it any further.
I have fairly good drivability; a bit of a hard start when cold but after 2 tries, runs to warm up fine. Good, not great, acceleration but then again I do NOT have a heavy foot. No smoke. No oil burning. In fact, I recently sent an oil sample out to Blackstone Labs for an engine oil analysis and everything was great; all below usual readings...Don't use the car that much, maybe 1,500 miles per year. 
I replaced the PCV as it was "popping" but the popping has not disappeared with the new one. I put a vacuum gauge on the motor and to my surprise, I am getting a low 10-12 reading and it is moving a few inches to either side of the 11 mark...
When I accelerate, the vacuum gauge smooths out and does what a "normal" engine would do, drops on acceleration to about 4 or 5 and then soars to 25 or so and settles back with a shake at about 11-12...I have snugged the intake manifold bolts and also the carb gasket bolts thinking a vacuum leak. No change. No leaks I can see with the carb cleaner method, etc...However, when I pull the brake booster line off the intake manifold to put the gauge on the motor, I can hear a sputtering in the vacuum and that is what is being conveyed to the gauge. 
Needless to say I have done a lot of studying of this subject in the past 2 weeks. I read worn valve guides would give such a reading. A possible blown head gasket, etc and so on, may also give such a reading, but my gut tells me this is not it.
Short of doing other engine tests, is it possible that the timing is retarded for this motor at 10 degrees BTDC? Is it possible that the 14-16 degrees was set this way for this motor/cam set up?
Before I reset the timing for maximum vacuum and ignore the timing light, what is the Forum's thoughts about my advancing the timing back to the 14-16 area? What are the risks with doing and running the motor at such an advanced point?
BTW, the dwell meter is telling me 40 degrees rather than the spec 30....I assume the Breakerless module is compensating for the retarded ignition...is that a reasonable thought?
Sorry for this long post, but I am enjoying an interesting learning experience. I am not an expert, so I thought I would ask the experts for some advice.
Engine had been rebuilt before I bought the car. While it is the original engine, there is a mild cam in the motor. "Normal" engine vacuum has been about 15 inches and there is a slight flutter, I assume from the overlap of the valves. The motor also has the Breakerless SE module in the distributor....
I noticed that the timing was set at what appeared to be about 14 or 16 degrees advanced.



I replaced the PCV as it was "popping" but the popping has not disappeared with the new one. I put a vacuum gauge on the motor and to my surprise, I am getting a low 10-12 reading and it is moving a few inches to either side of the 11 mark...


Needless to say I have done a lot of studying of this subject in the past 2 weeks. I read worn valve guides would give such a reading. A possible blown head gasket, etc and so on, may also give such a reading, but my gut tells me this is not it.
Short of doing other engine tests, is it possible that the timing is retarded for this motor at 10 degrees BTDC? Is it possible that the 14-16 degrees was set this way for this motor/cam set up?
Before I reset the timing for maximum vacuum and ignore the timing light, what is the Forum's thoughts about my advancing the timing back to the 14-16 area? What are the risks with doing and running the motor at such an advanced point?

BTW, the dwell meter is telling me 40 degrees rather than the spec 30....I assume the Breakerless module is compensating for the retarded ignition...is that a reasonable thought?

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