distributor curve springs?

I DO NOT LIKE using full manifold vacuum, but think what you are doing here

If you set initial timing (vacuum unhooked) at 16, and depending on what cam you have, and depending on what vacuum can you have, the think will be sitting there at idle with 16 PLUS whatever is in the vacuum can!!

I know he claims "that works" but I don't know specifically what to tell you. Manifold vacuum is not how I'm used to thinking.