Jerry, thanks for the detailed explanation. Your last point about connecting to the (-) terminal followed by Coilover's comment about clipping to the #1 wire is probably where I went wrong. The digital mmeter came with several different leads/probes, one of which clips around the plug wires like for a timing light and that's the one I used.... Sounds like that should be used for checking rpm, and I should have been using the battery type clips with one on the (-) coil lead and the other to a ground?
For my first question about vacuum - the rpm does drop when I pull the vac advance line from the carb, but the manifold vac looked to be unchanged at 21 Hg. Does the rpm drop mean that there was enough vacuum to pull the advance at idle and therefore raise the rpm? If I set timing to have 0 advance at TDC, and assuming all else is good, at idle the timing should still read zero with the vac advance connected and the engine idling, correct?
