aactually the e-brock and carter carbs are designed to run at around 5-6 psi.......
You're right about the "designed" part.
But....I ran an Edelbrock 750 for some time with 8.5-9 psi fp. I assumed
that my Carter street pump was putting out what it was spec'd
at (6 psi). After I switched to a Holley style carb and installed a fp gauge, I found out the pressure was too high and was causing some float issues with the new carb. Although the higher pressure didn't have an effect on the E-brock, the Holley didn't like it that high.
So, now I run a reg at 6.5.
As always, others may have different experiences.