Slant Six Carb Issues

My experience new fuel pumps will put out 8-12 PSI and rumors are Hollys are sensitive to fuel pressure. I used Daytonas on my dual carb setup which are Holly knockoffs from Argentina. They would occasionally flood over at idle. I found an original rebuildable Carter pump, bought a rebuild kit from Then and Now which has the same issue, 12 lbs of pressure. I bought an assortment of springs and found a spring light enough to give 4.5 lbs at the input to the carbs and it has run flawlessly for the last 3 years.