I run 4 psi on both my cars each having Edelbrock carbs. As long as your car runs great, there is no reason to run excess pressure.
Volume is important. Feed the pump with a larger line than you think. A lower pressure will actually lead to better fuel milage. The line to my regulator on my race car is an -8. My dual quads have right at 4psi on a different car. Good luck.