There was NO suggestion to tune to 4" of vacuum. Someone else was telling you about his situation.

The following is with vacuum advance disconnected and plugged:
In general, the suggestion was to increase initial advance until the vacuum at idle was at maximum. Then try starting the car with the engine warm and see if the engine "kicks back" against the starter. If that is so decrease initial advance by 2 degrees or so. This may take more than one iteration. When you have finally gotten the initial advance figured out, adjust the distributor to have no more than 36 degrees total advance, all in by 3000 or so rpm. This may mean shortening some slots or installing a bushing to limit total advance.

One thing for sure, the advance at idle should be rock-steady, the timing light showing the mark being still.

Once you have the initial set, and the total advance limited to the 35 or 36 degrees, then you reconnect the vacuum advance to the "ported vacuum" port on the carb. This should have no vacuum advance at idle, and when you open the throttle a little the vacuum advance works.

R.