Click here to download installation instructions (PDF)
PORTS AND FITTINGS
The fuel rail ports are tapped for 8AN ORB.
8AN ORB Adapter Fittings can be found HERE.
8AN ORB Fuel Pulse Dampers can be found HERE.
Fuel Pressure Gauge Adapters can be found HERE.
Appropriate fittings must be selected based on the specific application. Ample space around the fuel rail port(s) is necessary for larger accessories such as fuel pressure regulators, fuel pressure gauges, and fuel pulse dampers. To verify clearance, the dimensional drawings on the product pages can be used as a reference guide.
The Radium Engineering fuel rails have been confirmed to be compatible with the VQ35DE, VQ35HR, and VQ37VHR engine. However, there are other V6 Nissan VQ variations that are very similar.
The fuel rails are machined from 6061 aluminum and anodized black for compatibility with all popular fuel types including E85. Manufactured with a large internal bore, the fuel rail can support all necessary engine power requirements. Each rail has four 8AN ORB ports (2 end ports and 2 bottom ports). The fuel rail features 14mm injector bores and is compatible with the OEM injectors and any aftermarket injectors with OEM VQ fitment.
The fuel rails mount with stainless steel brackets and hardware.
The unique mounts permit fitment with all VQ engines. Additionally, the OEM injector clips can be reused for the VQ35HR and VQ35DE, as shown below.
With 4 ports on each rail (8 total), it is easy to add fuel system accessories such as a pressure transducer, fuel pulse dampers, etc. 
There is also opportunity to plumb the fuel rails in several different configurations, including parallel, series, or a return system. NOTE: Because of the OEM intake manifold mounting bosses, two Radium 14-0150 8AN ORB plugs must be used in 1 of each of the center ports for VQ35DE engines ONLY.
As shown below, the base kit (P/N: 20-0458) includes ONLY the fuel rails and associated mounting hardware. NO FITTINGS ARE INCLUDED.
OPTIONS
PLUMBING KITS:
20-0468 Fuel Rail Plumbing, Nissan VQ35DE
When used with the 20-0458 fuel rails, this kit permits a bolt-on, plug and play affair for VQ35DE engines. 
An SAE adapter connects to the OEM hard line underneath the vehicle. PTFE hoses route fuel to the rear fuel rail ports. 8AN ORB plugs and 6AN adapter fittings are included for all fuel rail ports. Additionally, 20-0460 is included to allow the OEM fuel pulse damper to be reused. 
20-0469 Fuel Rail Plumbing, Nissan VQ35HR and VQ37VHR
When used with the 20-0458 fuel rails, this kit permits a bolt-on, plug and play affair for both VQ35HR and VQ37VHR engines. 
An SAE adapter connects to the OEM hard line underneath the vehicle. PTFE hoses route fuel to the front fuel rail ports. 8AN ORB plugs and 6AN adapter fittings are included for all fuel rail ports. Additionally, two of the 20-0459 adapters are included to allow the OEM fuel pulse dampers to be reused. 
OEM FPD ADAPTERS:
20-0459 FPD Adapter, 8AN ORB, 27mm Bore
The OEM VQ35HR and VQ37VHR fuel pulse dampers can be reused with these adapters. One is required for each fuel pulse damper. NOTES:
1. If the 20-0469 plumbing kit (listed above) was purchased, these adapters are already included and thus, not necessary.
2. Use the 20-0460 OEM FPD adapter for the VQ35DE engine.
3. The VQ37VHR engine is NOT compatible with any Radium aftermarket dampers. Only the OEM dampers can be used using this adapter.
These can install into any fuel rail port provided there is adequate clearance. The Nissan VQ35HR is shown below.
20-0460 FPD Adapter, 8AN ORB, 11mm Bore, 39mm Spacing, M6
The OEM VQ35DE fuel pulse damper can be reused with this adapter. One is required. NOTES:
1. If the 20-0468 plumbing kit (listed above) was purchased, this adapter is already included and thus, not necessary.
2. Use the 20-0459 OEM FPD adapters for the VQ35HR and VQ37VHR engines. 
This adapter is shown below on the right side of the rail and listed above in options.
NOTE: Radium direct-mount pulse dampers are also compatible in some of the 8AN ORB ports in the VQ35DE and VQ35HR engine, as shown above.