Manufactured with a large 0.69" internal bore, the fuel rails can support all necessary engine power requirements. They are CNC machined from extruded 6063 aluminum, black anodized, and laser etched for a high quality surface finish. All end ports are machined with 8AN ORB (3/4-16 female) threads. The lower center ports can be used for optional adapters and are also tapped with 8AN ORB (3/4-16 female) threads.