A key is to make sure the distributor curb, carb and tuning specs are set up correctly for one or the other.

With a carb, I prefer ported vacuum. Keeping timing steady at idle helps stabilize idle. With manifold vacuum, vacuum and timing will jump around and harder to keep idle steady.

With FI and computer controlled timing, manifold vacuum. Set the timing curve as it needs to be. It can be vacuum in-sensitive at idle if desired. Or it can advance if idle speed drops to hold it steady (opposite what manifold vacuum does with a carb!).

Beyond that, manifold vacuum with a carb is a Chevy thing...