Add to Favorite Sellers. 25-302BK AEM Universal Adjustable Fuel Pressure Regulator – 20-150 PSI. Inlet: 2 x -6AN (9/16-18) Outlet: -6AN – Gauge Port: 1/8 in. NPT – Black; AEM’s Universal Adjustable Fuel Pressure Regulator (AEM 25 302BK) is capable of supporting enough fuel flow for engines up to 1000 horsepower. Customer Service & Feedback. So we have a chance to make it right – we want your repeat business! Check out the official Holley Performance. For more great deals!!