Flooding Edelbrock

I have a 1406 Edelbrock on my 340. At times when idleing it just pours gas into the front throats. After that I am staring a flooded motor. I am using a Holley electric pump and regulator, I am running 4 to 5 lbs.of psi. This problem doesn't happen all the time mostly when i start it after it has set in the garage for a couple of weeks and I start it and just let it set and run after it warms up I find this happening. I have changed carbs due to this happening before with another 1406 and I took it back and got another one now I have the same thing again. There is no return line on the car. Please if you don't have a answer don't comment. I don't need a he said she said thread started just some good solid answers.