I ran the Holley red pump for many years that uses the built in regulator and it was rock solid at 6 psi. In fact I ran 10.70's with the Holley red pump. Then switched to the Holley black pump about 2 years ago with this regulator here that I bought with the pump at a local speed shop. I set the regulator at 6 and it has been flawless for the 2 years its been on the car. And it runs 10.70's with it also. I only went to the larger Holley black pump because I was afraid the red pump would not supply enough fuel as its rated at 98 GPH I believe and the black is rated 140 GPH. But the red was giving me enough as it runs the same mph and et with the black pump and regulator. But its rock solid at the 6 PSI where I set it and I have had no problems. I have run Holley red and blue pumps since the 70's with no problems. I went with the black this time because its rated a bit larger then the blue. Ron