[dave.n]

Gonzo

Had exactly the same probs and I hate to say this but in the end I got rid of the Holley. However back to your problem, you have almost certainly got a sticky secondary float. I had three different reputable mechanics work on it they remedied mine by buying a overhaul kit and replacing the float needle (float needles can be bought seporate) and re-adjusting the float level to a level with the inspection screw. Float is on the bowl top and inspection screw is on the sides. I have to say that in the end after doing this several times I got it right. Haveing driven the car for about 9 months I decided to out the carb. Hope you have better luck.
Anyone got any other ideas as I know how infuriating let alone dangerous this problem is.