I have always thought that hooking up the vacuum advance should not go to manifold vacuum. During this time, I have read where someone will suggest hooking it up to manifold vacuum and everyone seems to say that would not work.

My question would be, what are the pros and cons of hooking up a vacuum advance to manifold vacuum?

I would think that you would see more initial timing "after" the engine has started and reached a minimum vacuum setting. More initial timing is what I have leaned towards to help in tuning my carbs. I would think that this would give more initial timing but would not cause more load on the starter especially during hot restarts due to not enough vacuum while the starter is engaged to allow more timing from the can.

I know that this is being used and I want to learn more about why it is done this way.

Thanks