IAG Performance IAG-ENG-H550DE IAG 550 Street D25 Cylinder Heads (No Cams & Lifters)

The IAG 550 Cylinder Heads are designed to function as an entry-level replacement for stock OEM heads. If your engine has suffered a catastrophic failure which requires replacement of your cylinder heads, or if you don't have OEM heads to start with, the IAG 550 Cylinder Heads are a perfect solution. These heads also work great for cars with basic bolt-on parts up to 550 BHP. These heads include upgraded GSC standard size valves, GSC Viton Valve Stem Seals, IAG Stage 1 Valve Springs with Titanium Retainers, and OEM Keepers. GSC S1 Camshafts are available with OEM valve lifter buckets. We also offer an optional chamber modification service (see below) for EJ20 heads to allow use on EJ25 short blocks. Each IAG 550 Cylinder Head Set starts with new OEM castings from Subaru of America. Next, you'll select whether or not you want to include our optional GSC camshaft package. If selected, these heads will include new GSC S1 Camshafts and OEM Lifter Buckets for valve adjustment. The bare castings are visually inspected and then fixtured into our in-house Centroid 5-axis CNC Machine. In the Centroid, the heads undergo a cam clearance machining process which removes material from the lifter area where larger lift and duration cam profiles are known to contact the castings. (Just in case you want to go bigger later.) Then the heads are fixtured in our Newen Valve Guide and Seat Machine to cut all intake and exhaust seats with a multi-angle valve job that suits the flow characteristics of GSC's standard size 36mm Intake and 32mm Exhaust valves. At this point, the heads' decks are resurfaced using our TS-3000 BlockMate, which cuts the aluminum to a smooth, even finish. Next, the heads are ultrasonically cleaned to remove debris and oils from the machining process. Finally, the heads are reassembled using GSC Stainless Intake and Exhaust Valves, GSC Viton stem seals, IAG-Stage 1 Valve Springs with Titanium Retainers, and OEM Valve Keepers.

This Part Fits:

Year	Make	Model	Submodel	Notes
2006	Subaru	Baja	Turbo
2008	Subaru	Forester	2.5 XT
2008	Subaru	Forester	Sports 2.5 XT
2008	Subaru	Forester	XT
2009	Subaru	Forester	XT
2010	Subaru	Forester	XT Premium
2011	Subaru	Forester	XT Premium
2012	Subaru	Forester	XT Premium
2013	Subaru	Forester	XT Premium
2010	Subaru	Forester	XT Sports
2011	Subaru	Forester	XT Sports
2012	Subaru	Forester	XT Sports
2011	Subaru	Forester	XT Touring
2012	Subaru	Forester	XT Touring
2013	Subaru	Forester	XT Touring
2009	Subaru	Impreza	2.5 GT
2010	Subaru	Impreza	2.5 GT
2006	Subaru	Impreza	WRX
2007	Subaru	Impreza	WRX
2008	Subaru	Impreza	WRX
2009	Subaru	Impreza	WRX
2010	Subaru	Impreza	WRX
2011	Subaru	Impreza	WRX
2012	Subaru	Impreza	WRX
2013	Subaru	Impreza	WRX
2014	Subaru	Impreza	WRX
2010	Subaru	Impreza	WRX GT
2009	Subaru	Impreza	WRX Premium
2010	Subaru	Impreza	WRX Premium
2011	Subaru	Impreza	WRX Premium
2012	Subaru	Impreza	WRX Premium
2013	Subaru	Impreza	WRX Premium
2014	Subaru	Impreza	WRX Premium
2010	Subaru	Impreza	WRX SE
2006	Subaru	Impreza	WRX TR
2007	Subaru	Impreza	WRX TR
2010	Subaru	Legacy	2.5GT
2011	Subaru	Legacy	2.5GT
2012	Subaru	Legacy	2.5GT
2007	Subaru	Legacy	GT Limited
2008	Subaru	Legacy	GT Limited
2009	Subaru	Legacy	GT Limited
2006	Subaru	Legacy	GT spec.B
2007	Subaru	Legacy	GT spec.B
2008	Subaru	Legacy	GT spec.B
2009	Subaru	Legacy	GT spec.B
2008	Subaru	Outback	2.5 XT
2006	Subaru	Outback	XT
2007	Subaru	Outback	XT
2008	Subaru	Outback	XT
2006	Subaru	Outback	XT Limited
2007	Subaru	Outback	XT Limited
2008	Subaru	Outback	XT Limited
2009	Subaru	Outback	XT Limited
2012	Subaru	WRX	Base
2013	Subaru	WRX	Base
2014	Subaru	WRX	Base
2013	Subaru	WRX	Limited
2014	Subaru	WRX	Limited
2014	Subaru	WRX	SE