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IAG Stage 3 Pocket Ported Heads Set Stage 3 Pocket Ported Heads w/+1mm GSC Valves D25 Casting(Cams/Lifters Sold Sep)

Engine Cylinder Head Set


IAG Stage 3 Pocket Ported Heads w/ +1mm GSC Valves for 06-14 WRX, 06-13 FXT, 07-09 LGT D25 Casting (Cams / Lifters Sold Separately).

  • New Head Castings, CNC Pocket Ported with +1mm GSC Valves, GSC Springs, GSC S2 Cams Included
Pricing: $3,629.99

Free ground shipping on all order over $100.00 (some exclusions may apply)


Subaru: WRX 13 - 14, Subaru: Baja 06 - 06, Subaru: Outback 07 - 09, Subaru: Forester 06 - 13, Subaru: Impreza 06 - 14, Subaru: Legacy 07 - 09

  • Recommendations / Warranty: For use with stock cams or mild duration cams Assembly and professional installation recommended. Workmanship/parts warranty will only be available for professionally installed cylinder heads.
  • Stage 3 Ported Head Package Includes: (x2) Brand New Subaru OEM D25 Cylinder Head Castings, (x8) GSC 37mm (+1mm) Intake Valves, (x8) GSC 33mm (+1mm) SuperAlloy Exhaust Valves, (x16) GSC Single Valve Springs & Titanium Retainers, (x16) OEM Valve Guides, (x16) GSC Valve Stem Seals, IAG Performance CNC Pocket Porting, Multi-Angle Valve Job, Machined Cam Lobe Clearance, Ultrasonic Cleaning

IAG Stage 3 Pocket Port Cylinder Head Package: The head package centers around our popular CNC pocket porting program which was developed over the last several years. Pocket porting removes excess OEM casting flash and the material underneath the valves. By smoothing and blending this area under the valve seat, significant flow capability can be achieved. The IAG Stage 2 pocket ported head package starts with brand new WRX OEM D25 head castings, directly from Subaru of America. The bare castings are visually inspected and then fixtured into our in-house Centroid 5-axis CNC Machine. This is one of the most advanced pieces of precision engine machining equipment in the world. The Centroid CNC ports the intake and exhaust runners under the valves and blends them to the valve seat. The heads then 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. Next, the heads are fixtured in our Serdi 3.0 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 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 Single Valve Springs and Titanium Retainers along with GSC Viton stem seals.


  • IAG-ENG-3030D
  • IAG-ENG-3030D
  • 887753779007
  • IAG Performance
  • New


Shipping Information

  • Item Requires Shipping
  • 72.0 lbs.
  • W16.0000” x H12.0000” x L20.0000”
  • Free ground shipping on all order over $100.00 (some exclusions may apply)

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