There are no high flow fuel rails available for the JDM (Version 8/9) STi Spec C engines which have the long runner intake manifold (no tumble generator valves). This adapter permits the use of any 2002+ Subaru top feed fuel rail. Furthermore, it was specifically designed for the Radium 20-0167-01 and 20-0167-02 Upgrade Fuel Rail Kits that use a Radium 20-0176 Fuel Pulse Damper (shown below).
This adapter IS NOT compatible with side-feed fuel rails or side-to-top feed conversion rails.
-CNC Machined Billet 6061 Aluminum-Bright Dip R5 Type-II Anodizing-Stainless Steel M8x1.25mm Hardware