GSC Exhaust Valve Set +1mm Oversize for Mitsubishi 4G63T – GSC2003-8
The GSC2003-8 exhaust valve set is designed for Mitsubishi 4G63T engines, featuring a +1mm oversize head diameter of 31.5mm, with a 6.6mm stem and 109.20mm overall length. Sold as a complete set of 8.
GSC Power-Division engineered this valve series to deliver exceptional flow and long-term durability for sport compact applications. Using advanced 3D simulation and design tools, they developed a stronger valve head that flows more efficiently. Each prototype is tested in its intended engine platform to ensure optimal performance. The result: reduced face distortion, improved sealing under high-stress conditions, and consistent output over the valve’s lifespan.
Key Features:
- Swirl-polished heads enhance airflow across the valve surface
- Back-cut design reduces weight, supporting higher RPM and boost without increasing valve spring seat pressure
- Micro-polished stems reduce oil retention and drag for smoother valve movement
- Exhaust valves are made from modified 23-8N stainless steel for high heat resistance and long-term reliability
- Valve tips are hardened or fused with stelite wafers, maintaining wear resistance within 5 Rockwell C of the rocker or tappet
- Tip heights are optimized to reduce tipping and simplify valve lash setup during installation
- Keeper grooves are precision-tuned to balance spring pressures and reduce the need for shims when paired with GSC spring and retainer kits
- Compatible with OEM keepers/locks or GSC upgraded versions; reusing old locks is not recommended for performance applications due to material wear
Fitment:
- 1990 Mitsubishi Eclipse GSX 2.0L Turbo AWD 4G63T
- 1991 Mitsubishi Eclipse GSX 2.0L Turbo AWD 4G63T
- 1992 Mitsubishi Eclipse GSX 2.0L Turbo AWD 4G63T
- 1993 Mitsubishi Eclipse GSX 2.0L Turbo AWD 4G63T
- 1994 Mitsubishi Eclipse GS 2.0L Turbo FWD 4G63T
- 1995 Mitsubishi Eclipse GS-T 2.0L Turbo FWD 4G63T
- 1996 Mitsubishi Eclipse GS-T 2.0L Turbo FWD 4G63T
- 1997 Mitsubishi Eclipse GS-T 2.0L Turbo FWD 4G63T
- 1998 Mitsubishi Eclipse GS-T 2.0L Turbo FWD 4G63T
- 1999 Mitsubishi Eclipse GS-T 2.0L Turbo FWD 4G63T
- 1990 Eagle Talon TSi 2.0L Turbo AWD 4G63T
- 1991 Eagle Talon TSi 2.0L Turbo AWD 4G63T
- 1992 Eagle Talon TSi 2.0L Turbo AWD 4G63T
- 1993 Eagle Talon TSi 2.0L Turbo AWD 4G63T
- 1994 Eagle Talon TSi 2.0L Turbo FWD 4G63T
- 1995 Eagle Talon TSi 2.0L Turbo FWD 4G63T
- 1996 Eagle Talon TSi 2.0L Turbo FWD 4G63T
- 1997 Eagle Talon TSi 2.0L Turbo FWD 4G63T
- 1998 Eagle Talon TSi 2.0L Turbo FWD 4G63T
- 1991 Mitsubishi Galant VR-4 2.0L Turbo AWD 4G63T
- 1992 Mitsubishi Galant VR-4 2.0L Turbo AWD 4G63T
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