The vacuum advance should go to ported vacuum on the carburetor. If it surges with the advance hooked up adjusting the advance with an allen wrench to raise the amount of vacuum necessary to move the advance should help. You might need a different advance unit with fewer degrees of advance if the allen wrench adjustment fails to cure the surge.
This is the original distributor to this engine. i have the advance slot filled in some to give it 32 total because it pings with any more than that. So can the vacuum take it even farther than the limited 32 total i have? Just not sure how the vacuum part works..
