IAG 550 Street Cylinder Heads Package - V25 Heads (Includes Cams & lifters / No chamber Mods) - 2004-2007 Subaru STI / 2004-2005 Forester XT / 2005-2009 Legacy GT

IAG 550 Street Cylinder Heads Package - V25 Heads + Cams & Lifters

STOCK REPLACEMENT HEADS FOR ENTRY-LEVEL PERFORMANCE

Introducing the IAG 550 Cylinder Heads, meticulously crafted to serve as a straightforward replacement for stock OEM heads. Whether your engine has endured a catastrophic failure necessitating cylinder head replacement or you're starting fresh without OEM heads, the IAG 550 Cylinder Heads offer an ideal solution. Engineered to accommodate vehicles equipped with basic bolt-on components, these heads are well-suited for power outputs up to 550 BHP. Featuring upgraded GSC standard size valves, GSC Viton Valve Stem Seals, IAG Stage 1 Valve Springs with Titanium Retainers, and OEM Keepers, these heads ensure reliable performance and durability. Optionally, GSC S1 Camshafts are available with OEM valve lifter buckets, providing further customization. Additionally, for EJ20 heads, we offer an optional chamber modification service, allowing compatibility with EJ25 short blocks.

 

CRAFTED WITH ALL-NEW COMPONENTS

The IAG 550 Cylinder Head Set begins with brand-new OEM castings sourced directly from Subaru of America. Your project's specifications, including the Year and Model of your vehicle, are carefully considered to ensure the right castings are selected. Additionally, you have the option to include our GSC camshaft package, which comprises new GSC S1 Camshafts and OEM Lifter Buckets for valve adjustment.

Once the bare castings undergo visual inspection, they are securely positioned in our in-house Centroid 5-axis CNC Machine. Here, the heads undergo a meticulous cam clearance machining process, removing material from the lifter area to accommodate larger lift and duration cam profiles, allowing room for potential future upgrades. Following this, the heads are placed in our Newen Valve Guide and Seat Machine to perform a comprehensive multi-angle valve job on all intake and exhaust seats, tailored to the flow characteristics of GSC's standard size 36mm Intake and 32mm Exhaust valves. Subsequently, the heads' decks are resurfaced to a smooth, even finish using our TS-3000 BlockMate. After ultrasonic cleaning to eliminate debris and oils from the machining process, the heads are meticulously reassembled. This includes the installation of GSC Stainless Intake and Exhaust Valves, GSC Viton stem seals, IAG-Stage 1 Valve Springs with Titanium Retainers, and OEM Valve Keepers.

 

GSC S1 CAMSHAFT AND LIFTER BUCKET COMBINATION

For those aiming to unleash greater power, opting for the GSC Power-Division billet S1 camshafts within your IAG 550 Head Package is paramount. These camshafts are engineered to optimize power output without compromising low-end performance, delivering enhanced power and torque throughout the RPM spectrum. Ideal for applications with stock frame upgraded turbos or seeking power upgrades of up to 500 WHP, these camshafts are meticulously paired with all-new OEM valve lifter buckets. Additionally, our specialized fixture ensures precise bench lash adjustment, although it is recommended to verify and fine-tune the final lash upon head installation.

 

IAG 550 Street Cylinder Head Package Includes:

• (x2) Brand New Subaru OEM WRX or STI Cylinder Head Castings
• Multi-Angle Valve Job
• Machined Cam Lobe Clearance
• Resurface
• Ultrasonic Cleaning
• (x8) GSC 36mm (Standard) Intake Valves
• (x8) GSC 32mm (Standard) Exhaust Valves
• (x16) IAG Stage 1 Valve Springs & Titanium Retainers
• (x16) GSC Valve Stem Seals

Camshaft Package Also Includes:

• GSC S1 Camshafts
• (x16) OEM Lifter Buckets
• Bench Valve Lash Service (Final Lash Should be Checked and Adjusted Once Heads are Installed)

 

Note: This Package does NOT include Chamber Modification.