This Nissan Silvia fuel rail is specifically designed for the SR20DET S14/S15 OEM intake manifold. Manufactured with a 0.69" large internal bore, the fuel rail can support all necessary engine power requirements. The rail is CNC machined from solid 6061 aluminum and black anodized for a high quality surface finish. The included insulating spacers mount the rail to the OEM intake manifold bosses thermal isolation. The Radium fuel rail converts the OEM side feed fuel injector setup to top feed, allowing the use of high flow fuel injectors (not included). The fuel injector bores are 14mm ID. The kit is designed for specific upper and lower O-ring spacing, as depicted. Below are some of the many fuel injectors that are a direct fitment: Injector Dynamics ID1050-XDS-34-14-14Injector Dynamics ID1300-XDS-34-14-14Injector Dynamics ID1700-XDS-34-14-14Injector Dynamics ID2600-XDS-34-14-14 To resist oxidation corrosion, the lower billet aluminum injector seats are anodized and laser etched. They are O-ring sealed and designed for 14mm top feed injectors. This kit is compatible with all fuel types including popular alcohol mixtures such as E85. The OEM 2-bolt IACV bypass hard line is replaced by a billet aluminum IACV spacer kit to gain clearance for the top feed fuel rail. An anodized aluminum barb adapter and rubber hose is supplied to reroute the charge pipe hose externally to the manifold. One gasket is included for the IACV spacer. INCLUDED: All parts listed below are included for a trouble and leak-free installation. -Black Anodized Aluminum Fuel Rail-Thermal Insulating Spacers (x 3)-Thermal Insulating Washers (x 3)-Radium 20-0161, Green Anodized Aluminum 25mm Injector Seats (x 4)-Radium 20-0162, Black Anodized Aluminum IACV Spacer Kit-Radium 18-0014, IACV Gasket, SR20DET S14/S15 (x 1)-Black Anodized Aluminum IACV Barb Adapter -Rubber Hose and OEM Clamp for IACV-Stainless Steel M8x 1.25 Mounting Bolts (x 3)-Stainless Steel M6x 1 Mounting Bolts (x 3) Instruction PDF