Since your set on using the dual point distributor, I used to set up a dual point in my 67 GTO by removing the distributor, clamping it on a vice, isolating one set of points with a business card, driving the distributor with a drill and setting the points with a dwell meter. I had no luck setting them with a feeler gauge and at the time I didn’t have the extra cash to have it professionally setup at the speed shop. It seemed to work as the engine ran pretty well after.
