I don't think it's 3 or 4 psi when I first fired the car up the pressure kept dropping I would adjust it up then the next day it would drop again this went on a couple of times until it finally stayed at 7 psi I think the gauge was screwing up and I kept adjusting the regulator up thinking it was the regulator until i had it turned up to the pumps max which I think is 9 or 11 psi ( it's a Holley black top pump) I just drove the car and it was much much better but it still had a little sputter I dropped the fuel pressure about another 1/2 pound and the sputter is gone and I can pull 2 gears at full throttle and it's not running out of fuel. I do have to say it's nice to feel mopar power again man this 512 rips