IAG Stage 2 Pocket Ported Cylinder Heads for 07 STI V25 Casting (Cams / Lifters Sold Separately). 2016-subaru-wrx sti-limited Unique Fire Rings help contain

Unique Fire Rings help contain extreme cylinder pressures

This is a common practice on many street vehicles as well as race cars that utilize a rotated turbo system

Pocket porting removes excess OEM casting flash and the material underneath the valves

The case halves are then CNC machined for our new Fire-Lock head gasket solution that is loosely derived from diesel technology where a counterbore step is machined around each cylinder bore allowing specially sized fire rings to drop into the machined area and head gasket bores

Fits all factory engine bay ancillaries (i

IAG Stage 2 Pocket Ported Cylinder Heads for 07 STI V25 Casting (Cams / Lifters Sold Separately). 2016-subaru-wrx sti-limited Unique Fire Rings help containIAG 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 V25 head castings,