There is no hole in the intake manifold, the carb relies on the notch in the spacer to provide the passage.
Also, I have noticed on more than one Rochester that the casting that holds the power valve ball that the power piston contacts tends to warp, keeping the power valve from retracting reliably.
The other thing that you will want to check is the float level. If the float level is too high and the gasket on the inside of the air horn is leaky (a common problem with Rochesters) you will get fuel dumping down the inside of the carb.
