GSC Power Division 3026-8 Manganese Bronze Intake Valve Guides Stopper Subaru EJ

Vehicle Fitment

• 2002-2014 Subaru Impreza WRX (EJ205, AWD)
• 2004-2021 Subaru Impreza WRX STI (EJ257 / EJ257B, AWD)
• 2005-2012 Subaru Legacy GT / Outback XT (EJ255, AWD)
• 2004-2013 Subaru Forester XT (EJ255, AWD)
• JDM 1999-2007 Subaru Impreza WRX STI (EJ207, AWD)

Fitment Notes

• Stopper-style guide - verify that your cylinder head is machined to accept a guide with a stopper collar before ordering; the traditional smooth-style intake equivalent is GSC 3028-8.
• Stopper-style exhaust equivalent for this engine family is GSC 3025-8.
• Fits EJ205, EJ207, EJ255, EJ257, and EJ257B engines - does not fit EJ20 SOHC or non-turbocharged EJ25 variants with different valve stem or guide boss specifications.
• Standard OD sizing; light honing of the guide boss may be required depending on head condition and target clearance specification.
• Oversized OD options (+0.001" and +0.003") are available individually for heads requiring bore service.

Features

• Manufactured from true C67410 Manganese Bronze for superior lubricity, heat conductivity, and long-term wear resistance over OEM cast iron guides.
• Stopper collar provides a positive depth-stop during installation, ensuring all eight intake guides seat to a consistent depth without repeated measuring.
• CNC-turned on dedicated precision turning centers to maintain the tightest OD-to-ID concentricity tolerances in the aftermarket.
• True-to-size OD minimizes guide boss honing on heads that don't require bore service, reducing overall installation time.
• Shorter intake-specific length (1.560" / 39.62mm) correctly sized for EJ-series intake port geometry.
• Compatible with GSC EJ-series intake valves, valve stem seals, and spring kits for a complete matched valvetrain rebuild.

Specifications

• Position: Intake
• Style: Stopper Style (with collar)
• Material: Manganese Bronze (proprietary C67410 blend)
• Total Length: 1.560" / 39.62mm
• Outer Diameter: 0.4357" / 11.07mm
• Valve Stem Diameter: 6mm
• Application: Subaru EJ205, EJ207, EJ255, EJ257, EJ257B

Included Components

• 8x GSC Power Division Manganese Bronze Stopper-Style Intake Valve Guides (Standard OD)

Product Description

The GSC Power Division 3026-8 is a set of eight stopper-style Manganese Bronze intake valve guides engineered for Subaru's turbocharged EJ20 and EJ25 engine family, covering the EJ205, EJ207, EJ255, EJ257, and EJ257B across the WRX, WRX STI, Legacy GT, Outback XT, and Forester XT. Made from true C67410 Manganese Bronze rather than OEM cast iron, these guides deliver improved lubricity against the valve stem, better thermal conductivity, and significantly longer service life - particularly important in the intake guide position during high-boost builds with aggressive cam profiles and elevated RPM targets.

At 1.560" / 39.62mm, the intake-specific length is properly sized for the EJ-series intake port depth, while the stopper collar eliminates the need to manually verify seating depth during installation - all eight guides drive to the same consistent position automatically. Precision CNC-turned to the tightest concentricity tolerances available in the aftermarket, minimal honing is required on undamaged guide bosses. For heads requiring bore service, individually sold +0.001" and +0.003" oversized options are available. Builders preferring a smooth guide without a stopper should reference GSC 3028-8.

A core component of any EJ-platform head build, the 3026-8 pairs directly with GSC's EJ-series intake valves, Viton valve stem seals, and beehive or conical spring kits for a fully matched high-performance valvetrain on any WRX, STI, Legacy GT, Outback XT, or Forester XT.