The Subaru Impreza 2.5i (EJ253) and JDM Ver8/9 (EJ207) STi intake manifolds are great solutions for eliminating the tumble generator valves on modified engines.
These Radium Engineering adapters permit the use of any OEM or aftermarket Subaru top feed fuel rail.
The slotted hole positioning below is specifically for the Subaru EJ253 intake manifold. Moving the adapters outwards allows fuel rail fitment for the Ver 8/9 JDM EJ207 STi intake manifold.