Vacuum Advance vs. Mechanical Advance—What's the Difference and Which is Right for You?

Anyone using manifold vacuum advance?

A masters method for vacuum advance tuning

How Ignition Timing Works: Vacuum and Mechanical Advance Explained

Vacuum advance units advance the spark through the distributor ... | Filo

this is a quick check on your distributor, vacuum advance to see if it's functioning properly. Customer reporting that the car surges up and down while cruising. I used a cheap harbor freight vacuum pump #63391 | Bowtie Specialties