Harvester,
It might be of academic interest to some but it is of practical interest to others. Thanks for the information and for clearing answering questions.
So, if maximum rpm that I will push my 261 is less than 4,000 rpm, do you see any advantage using a dual point distributor?
Your last paragraph confirms what I have empirically confirmed to be a useful and easy technique for setting timing. I have found that the vacuum technique (with a little "back off" from the advance-side of maximum vacuum) is better than the maximum rpm method (a method commonly done "by ear").
Thanks,
Tim
