What is the correct amount of vacumn advance?

Depending on your set up, initial timing could be let`s say 15*btdc and a mechanical advance of 18* for 33*advance. Vacuum advance could be 17* for a total of 50*. It`s relatively rare for all things to come together at the right time that your timing would ever advance to 50* like that, but if you do a lot of around town driving it`s more likely. The vacuum advance will help with your gas mileage at low rpms around town. At WOT the vacuum advance doesn`t come into play so your 32* or whatever you choose is right where you want it. I still run my vacuum advance and with all in I`m at approximately 52*.