Still fighting this problem, Revs drop to zero if car not held at 1500 rpm.  I have plenty of volts, have tried my spare carb, looked at the distributor wiring.
No difference.  292 w/points, alternator conversion (happened before and after conversion. As an aside, I bought the alternator conversion off ebay.  It is a good installation, but the directions could be more specific (or perhaps I could be smarter...). A well spent $189.  Any ideas would be appreciated.