GSC Stopper Style Intake Valve Guide Set of 8 WRX 15-21 / BRZ / FR-S / 86 13-20 | 3106-8

Product Fitment:

2015-2021 Subaru WRX

2013-2020 Subaru BRZ

2013-2016 Scion FR-S

2017-2020 Toyota 86

The GSC Power-Division Stopper Style Intake Valve Guide is designed specifically for FA20-engine Subaru WRX, BRZ, and Scion FR-S models. Built from premium manganese bronze, this valve guide offers tight tolerances, durable construction, and options for standard or oversized bore sizing (+0.001″ or +0.003″) to suit rebuilt or high-performance heads.

Key Features:

• Constructed from C67410 manganese bronze for exceptional temperature and wear resistance.

• Stopper style design ensures precise head location and prevents guide pull-out during high-RPM use.

• Available as a set of 8 guides (standard size) or as single oversized units (+0.001″ or +0.003″).

• Dimensions: Length ~ 1.654″ (42.01 mm), Outer Diameter ~ 0.3964″ (10.07 mm); fits 5.5 mm valve stems.
  

Benefits & Use Cases:
When building a performance FA20 engine — whether naturally aspirated or turbocharged — the factory valve guides can limit reliability. The GSC Power-Division guides improve rigidity, tolerance control, and longevity, allowing stable valve operation even under high boost or RPM conditions.

Installation Notes:

• Ensure the cylinder head is properly prepped: clean bore, correct depth, and accurate press fit.

• Choose the appropriate size based on head condition or rebuild requirements.

• After installation, verify valve stem clearance, guide height, and spring setup.

• Ideal for track, street, or high-performance builds where precision matters.