GSC Power Division 3003-8 Manganese Exhaust Valve Guides Stopper Style for 4G63T

Vehicle Fitment

• 1992-2006 Mitsubishi Lancer Evolution I-IX (4G63T, AWD)
• 1990-1999 Mitsubishi Eclipse GST / GSX (4G63T, FWD/AWD)
• 1996-1999 Mitsubishi Eclipse Spyder GST (4G63T, FWD)
• 1990-1994 Mitsubishi Eclipse GS (4G63, FWD)
• 1990-1998 Eagle Talon TSi (4G63T, FWD/AWD)
• 1990-1994 Plymouth / Mitsubishi Laser RS (4G63T, FWD/AWD)
• 1991-1992 Mitsubishi Galant VR4 (4G63T, 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 equivalent is GSC 3001-8.
• 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 a proprietary blend of C67410 Manganese Bronze for superior lubricity, heat transfer, and long-term wear resistance over OEM cast iron guides.
• Stopper collar provides a positive depth-stop during installation, ensuring consistent guide seating depth across all eight exhaust positions.
• CNC-turned on dedicated precision turning centers to maintain the tightest OD-to-ID concentricity tolerances in the segment.
• True-to-size OD minimizes guide boss honing on heads that don't require bore service, reducing installation time.
• Profile shaped to improve exhaust port airflow compared to the OEM guide design.
• Compatible with GSC 4G63 exhaust valves, valve stem seals, and spring kits for a fully matched valvetrain rebuild.

Specifications

• Position: Exhaust
• Style: Stopper Style (with collar)
• Material: Manganese Bronze (proprietary C67410 blend)
• Total Length: 1.950" / 49.53mm
• Outer Diameter: 0.4750" / 12.07mm
• Valve Stem Diameter: 6.6mm
• Application: Mitsubishi 4G63 / 4G63T (DSM & Evo I-IX)

Included Components

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

Product Description

The GSC Power Division 3003-8 is a set of eight stopper-style Manganese Bronze exhaust valve guides engineered for the Mitsubishi 4G63 and 4G63T engine used across all DSM platforms and Lancer Evolution I through IX. The stopper collar is the key differentiator from the traditional smooth 3001-8 - it seats against the guide boss during installation, providing a positive mechanical depth stop that ensures every guide is driven to the exact same seating depth without measuring or secondary verification. This makes the install process faster and more consistent, particularly during full head builds.

Like all GSC guides, these are turned from a proprietary blend of C67410 Manganese Bronze on CNC turning centers holding the tightest concentricity tolerances available in the aftermarket. The result is a guide that fits precisely, requires minimal honing in good-condition heads, and delivers improved lubricity and heat dissipation compared to the factory cast iron guides. The exhaust-specific dimensions (1.950" / 49.53mm length) are correctly sized for the 4G63 exhaust port and match direct-replacement depth requirements.

Ideal for performance head builds on any 4G63T platform, the 3003-8 pairs seamlessly with GSC exhaust valves, valve stem seals, and spring kits. For heads that have been bored, individually sold +0.001" and +0.003" oversized guides are available separately.