IAG Stage 2 Pocket Ported Heads w/ GSC S2 Cams for 08-17 STI W25 Casting. 2005-subaru-impreza-wrx sti IAG's in-house honing process is

IAG's in-house honing process is able to set piston to wall clearances tighter for a quieter running engine

The IAG MAF (Mass Air Flow Sensor) mounting flange is manufactured from aluminum and is designed to be welded onto a custom 3" aluminum pipe

Each package starts with brand new WRX S20 OEM head castings

Note: This kit does not work with the V3 AOS

Our latest bracket design relocates the alternator without requiring any modifications to the OEM bracketry or oil dip stick mounting for the EJ25

IAG Stage 2 Pocket Ported Heads w/ GSC S2 Cams for 08-17 STI W25 Casting. 2005-subaru-impreza-wrx sti IAG's in-house honing process isIAG Stage 2 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 STI OEM W25 head castings,