Edelbrock Performer RPM fuel pumps feature a high-quality, 3-stage polished finish. The unique valve design of these pumps improves flow quantity and quality and will support engines with up to 600 hp. The high-volume, 3/8 in. NPT inlet and outlets surpass the capacity of many other pumps. Edelbrock Performer RPM fuel pumps produce 6 psi and do not require a regulator. Best of all, the clockable lower housing can be rotated for the best inlet and outlet alignment. They are designed for use with gasoline only. This is our reccomendation for the 602 & 604 Crate motors.