I have had the same issue you are having. I bought a vacuum advance a few years ago from Oreilly Auto parts for a 1955 Chevy first series truck. When I put it on, it mounted differently than the original, and it resulted in a bind that would not allow the distributor to rotate. My advice is get on that is designed for the year of your engine. Also, there is a small L shaped tab that protrudes up through the area of the vacuum advance called the "octane selector"/timing advance marks. That little tab prevents the distributor from rotating to far. If that little tab is bent over to much, it will cause severe binding and no distributor rotation at all.
