Brand New Subaru Wrx Sti B25 Cylinder Heads Premium Aftermarket Bare Castings (Right Side)

Subaru WRX STI B25 Right Side Cylinder Head – Brand New Bare Casting

Passenger Side Replacement for 2.5L DOHC Turbocharged Engines

Upgrade your Subaru’s EJ-series boxer engine with this premium, brand-new B25 Right-Side (RH) passenger-side bare cylinder head. Specifically engineered for 2004–2006 turbocharged EJ255 and EJ257 platforms, this aftermarket casting is designed to address the intense thermal and structural demands of forced induction. Unlike standard factory replacements, this “reinvigorated” B25 casting features reinforced wall thickness in critical high-stress areas, providing a significant increase in durability and resistance to the deck warping common in high-boost applications.

As a bare casting, this unit offers professional engine builders and Subaru enthusiasts the ultimate technical flexibility. It serves as a “zero-hour” foundation, allowing for the custom installation of performance valves, high-rate springs, and aggressive camshaft profiles tailored to specific power goals. Every B25 head undergoes precision CNC machining to meet or exceed original equipment (OE) dimensional tolerances, ensuring absolute deck flatness for a superior multi-layer steel (MLS) head gasket seal. Whether you are performing a factory-spec restoration or a high-horsepower build for an STI, Forester XT, or Legacy GT, this reinforced B25 head provides the structural integrity and cooling capacity required for long-term reliability.

🛠️ Engineering & Performance Features

• Superior Durability: Crafted from high-strength alloys with increased wall thickness to prevent common cracking issues found in high-boost applications.
• Passenger Side Specific: Specifically machined for the right side (Bank 1) of the Subaru 2.5L flat-four engine.
• Customizable Bare Casting: Delivered without internals, allowing you to select your own valves, springs, and camshafts for a tailored setup.
• Rigorous Quality Control: Every head is thoroughly cleaned, vacuum tested, and pressure tested to exceed OEM standards.

📊 Technical Specifications

• Engine Type: Subaru 2.5L DOHC Turbocharged (EJ25)
• Casting Designation: B25 (Right/Passenger Side)
• Condition: Brand New Aftermarket
• Format: Bare Casting (Components not included)

🚛 Fitment Data

Compatible with 2.5L DOHC Turbocharged Models:

• Subaru Impreza WRX STI: 2004–2005
• Subaru Forester XT: 2004–2005
• Subaru Baja Turbo: 2004–2005
• Subaru Legacy GT: 2005–2006

Important fitment note: This listing is for the RIGHT (Passenger) side only. Please ensure your vehicle uses the B25 casting before ordering.