slowgoer,
Yes, that is how it is suppose to work.
It sounds like the vacuum line is coming off the wrong spot in the system. A Rochester carburetor has its ported vacuum tap right next to the idle adjustment screw.
I have heard you can time this engine by ear...rotate the distributor for maximum idle speed , than roll it back (CCW) a "hair". I have no clue if the actually works.
I think a timing light would be much more accurate..is 60 a 'old guy'.
Stuart