I had the same problem on a Chevy smallblock with an Edelbrock fuel pump. If flooded and leaked gas (even caught fire once) and all sorts of unpleasant stuff...with several different carbs.

I, too, put a pressure gauge on it and the pressure appeared to be fine. But out of desperation I put a pressure regulator on it, turned it down almost to its mininmum setting and never had another problem with it. Regulators are cheap...I think I paid under $20 for it...and it might be worth a try.