Heads & Cams

IAG Stage 1 Cylinder Head Package: IAG's Stage 1 cylinder heads are intended for those looking for a cost-effective OEM+ replacement. Each package starts with brand new WRX S20 OEM head castings, directly from Subaru of America. The bare castings are...

IAG Stage 1 Cylinder Head Package: IAG's Stage 1 cylinder heads are intended for those looking for a cost-effective OEM+ replacement. Each package starts with brand new WRX STI OEM head castings, directly from Subaru of America. The bare castings are...

IAG Stage 1 Cylinder Head Package with GSC Stage 1 Cams: IAG's Stage 1 cylinder heads are intended for those looking for a cost-effective OEM+ replacement. Each package starts with brand new WRX S20 OEM head castings, directly from Subaru of America. The...

IAG Stage 1 Cylinder Head Package with GSC Stage 1 Cams: IAG's Stage 1 cylinder heads are intended for those looking for a cost-effective OEM+ replacement. Each package starts with brand new WRX STI OEM head castings, directly from Subaru of America. The...

IAG 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...

IAG Stage 2 Pocket Port Cylinder Head & Cam 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...

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...

IAG Stage 3 Pocket Port Cylinder Head & Cam 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...

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...

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...

IAG Stage 4 S20 Ported Heads with +1mm GSC Valves & Cams: IAG's Stage 4 Cylinder Head Package utilizes a CNC porting program for the S20 heads that was developed over the past five years and tested on the most successful high-horsepower Subaru's. The...

IAG Stage 4 Ported Heads with +1mm GSC Valves & Cams: IAG's Stage 4 Cylinder Head Package utilizes a CNC porting program for the WRX STI heads that was developed over the past five years and tested on the most successful high-horsepower Subaru's. The...

IAG Stage 4 CNC Ported Heads with +1mm GSC Valves: IAG's Stage 4 Cylinder Head Package utilizes a CNC porting program for the WRX STI heads that was developed over the past five years and tested on the most successful high-horsepower Subaru's. The ported...

IAG's Stage 4 Cylinder Head Package utilizes a CNC porting program for the S20 heads that was developed over the past five years and tested on the most successful high-horsepower Subaru's. The ported head package starts with brand new S20 WRX OEM head...

IAG's Stage 4 Cylinder Head Package for the 2015-20 WRX utilizes a CNC porting program for the AW20 heads which was developed over the past year and tested on the most successful high-horsepower Subaru's. The ported head package starts with brand new...

IAG Stage 5 CNC Ported Cylinder Heads w/ +1mm Ferrea Valves: IAG's Stage 5 Cylinder Head Package utilizes a CNC porting program for the WRX STI heads that was developed over the past five years and tested on the most successful high-horsepower Subaru's...

IAG's Stage 5 Cylinder Head Package utilizes a CNC porting program for the AW20 heads that was developed over the past five years and tested on the most successful, high-horsepower, Subarus. The ported head package starts with brand new AW20 FA20 WRX DIT...

IAG Stage 5 CNC Ported Cylinder Heads: IAG's Stage 5 Cylinder Head Package utilizes a CNC porting program for the Subaru WRX STI heads that was developed over the past five years and tested on the most successful high-horsepower Subaru's. The ported head...

IAG's Stage 5 Cylinder Head Package utilizes a CNC porting program for the S20 heads that was developed over the past five years and tested on the most successful high-horsepower Subaru's. The ported head package starts with brand new S20 2002-05 WRX 2...

IAG's Stage 5 Cylinder Head Package utilizes a CNC porting program for the S20 heads that was developed over the past five years and tested on the most successful high-horsepower Subaru's. The ported head package starts with brand new S20 2002-05 WRX...

The Subaru FA20 cylinder heads use pressed-in freeze plugs from the factory. It's common for the plugs to fall out, lose coolant externally or even internally into the oil. Unfortunately, most of the freeze plugs are located behind the timing cover and...