I decided to try the manifold vacuum to see what changes occur in the cruising/idling A/F readings, idle quality (lower idle speed and higher vacuum reading), improved cruising torque, and I like the idea of having a lower initial timing for hot restarts. Having manifold vacuum is like having a start retard setup. During cranking mine will see 18 degrees of timing which will help on hot restarts in the Summer. Then when the engine fires the timing will jump up to 30-32 degrees at idle.
My current idle A/F is richer than most in the 13.5-13.8 range so that when I put the tranny in D with the brake applied, my idle does not go lean. I know that there are members running their idle A/F's into the mid to high 14's ( I assume that these are stick cars) but I can not get mine that lean and keep a good steady idle while in D, well at least not yet. I hope to start driving the car in the next week or two and get my tuning dialed in.

There is more to it than just making the idle richer. There are other benefits that I want to pursue from the manifold vacuum theory especially on my street driven only car.