If you go with any newer than 67 dizzy (including the dui) you can just run the vacuum advance direct off the manifold. Thats not how the factory did it but most of us find it to perform quite well.
Vacuum advance is a benefit for engines that dont run at constant loads. A constant load would be a tractor, boat, airplane, genarator, things like that.
My recently rebuilt Cadillac motor tried to eat itself and stranded me out of town on the interstate yesterday so my schedule is pretty screwed up and I have not had time to throw a vacuum gauge on the mustang.
Vacuum advance is a benefit for engines that dont run at constant loads. A constant load would be a tractor, boat, airplane, genarator, things like that.
My recently rebuilt Cadillac motor tried to eat itself and stranded me out of town on the interstate yesterday so my schedule is pretty screwed up and I have not had time to throw a vacuum gauge on the mustang.