Engines and Components› Cylinder Heads and Components

IAG Performance

550 Street Cylinder Head Package

$5,399.99

SKU: IAG-ENG-H550SCL

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Overview

The IAG Performance 550 Street Cylinder Head Package is designed as an entry-level replacement for stock OEM heads. This package is suitable for engines that have suffered catastrophic failure or for builds requiring new cylinder heads. It is also a good option for vehicles with basic bolt-on modifications and a power target of up to 550 BHP.

Each set begins with brand-new Subaru OEM WRX or STI cylinder head castings. The package includes a multi-angle valve job, machined cam lobe clearance, resurfaced decks, and ultrasonic cleaning. It comes with GSC 36mm intake valves, GSC 32mm exhaust valves, IAG Stage 1 valve springs with titanium retainers, and GSC Viton valve stem seals.
Show original supplier description
The IAG Performance 550 Street Cylinder Head Package serves as a robust entry-level replacement for OEM cylinder heads, ideal for catastrophic engine failures or as a foundation for performance builds. These heads are engineered to support vehicles with basic bolt-on modifications and aim for power levels up to 550 BHP. Each package starts with new Subaru OEM WRX or STI cylinder head castings. The machining process includes a multi-angle valve job, cam lobe clearance machining, deck resurfacing, and ultrasonic cleaning. Standard inclusions feature GSC 36mm intake valves, GSC 32mm exhaust valves, IAG Stage 1 valve springs with titanium retainers, and GSC Viton valve stem seals. An optional GSC S1 camshaft package is available, which includes OEM lifter buckets and a bench valve lash service. These cylinder heads are intended for use with stock or mild duration camshafts. Professional installation is recommended, and the manufacturer's workmanship/parts warranty is contingent upon professional installation. It is important to check and adjust the final valve lash once the heads are installed.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandIAG Performance
Part NumberIAG-ENG-H550SCL
CategoryEngines and Components
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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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