GSC Power Division Subaru EJ & FA Valvetrain

• Billet camshafts in S1, S2 and S3 profiles for EJ205, EJ25 single AVCS, EJ255/EJ257 intake AVCS, EJ257 dual AVCS and EJ20 JDM/Euro STI heads
• Intake and exhaust valves in chrome polished, 21-4N, 23-8N and super alloy materials, in standard and +1mm head sizes
• Valve spring and titanium retainer kits, including single, dual, beehive and conical designs
• Chromoly and steel valve spring seats, titanium retainers and valve keepers
• Manganese bronze valve guides in traditional and stopper styles, plus Viton valve stem seal sets
• DLC shim bucket tappets for EJ applications

Select by engine code first: EJ205 (WRX 2002-2005), EJ207 (JDM/Euro STI), EJ255 and EJ257 (2.5L turbo), EJ20/EJ25 SOHC, FA20F (WRX 2015-2021), FA20 (BRZ/86), FA24F (WRX 2022+) and FA24D (BRZ/GR86 2022+). Chassis codes listed against some items include GC8, GDA, GGA, GDB, GRF, GVF and VAB.

Camshaft fitment also depends on AVCS type - single/intake AVCS versus dual AVCS (STI 2008+) - and some FA20 items are split between 2012-2013 and 2014+ production. Valve sizes are listed as standard (STD) or oversize (+1mm), and oversize valves may require machining of the seats. Spring kits are often matched to specific retainers and seats, so check the kit reference codes noted in the product titles.

Valvetrain components are cylinder head internals and require the head to be removed and disassembled. Machining is typically involved, including guide installation and honing, seat cutting for oversize valves, valve lapping and checking installed spring heights, retainer-to-seal clearance and valve-to-piston clearance.

You'll generally need a valve spring compressor, height micrometer, guide drivers or a press, a torque wrench, new head gaskets and head bolts or studs, and assembly lube. Camshaft changes may also call for updated ECU tuning. Installation by a qualified professional workshop or engine machinist is strongly recommended.

Do GSC camshafts fit both single and dual AVCS EJ heads?
No. Camshafts are application-specific - choose the set listed for your AVCS configuration, such as EJ255/EJ257 intake AVCS or EJ257 dual AVCS (STI 2008+).

Are FA20 parts listed for BRZ/86 the same as WRX FA20F parts?
Not always. The naturally aspirated FA20 (BRZ/86) and turbocharged FA20F (WRX 2015-2021) are listed separately, so match the engine code shown in the title.

Do I need matching retainers and seats with a spring kit?
Many kits include retainers and seats. Where springs or retainers are sold individually, use the GSC kit reference noted in the product title to pair them correctly.