Cylinder Heads & Parts

The IAG Long Block Engine Basic Installation Kits provide all of the basic components needed to install one of our EJ25 Long Block Engine Packages in one complete kit. All fluids for initial break-in are included. Just select the kit which fits your year...

The IAG Long Block Engine Basic Installation Kits provide all of the basic components needed to install one of our FA20F DIT WRX Long Block Engine Packages in one complete kit. All fluids for initial break-in are included. Components Included: (x2)...

The IAG Performance / JE Pro Seal Subaru MLS head gaskets were designed specifically for use with IAG's 14mm Head Stud Sets. The gaskets are manufactured from stainless steel material and feature enlarged head stud holes to clear 14mm head studs without...

The IAG Performance / JE Pro Seal Subaru MLS head gaskets were designed specifically for use with IAG's 14mm Head Stud Sets. The gaskets are manufactured from stainless steel material and feature enlarged head stud holes to clear 14mm head studs without...

After years of research and development testing, the IAG Performance Fire-Lock™ head gasket is the newest solution to preventing head gasket failure on high horsepower and high boost Subaru EJ25 engines. This solution is loosely derived from diesel...

The IAG Performance Fire-Lock head gasket solution was created after years of research and development testing to prevent head gasket failure on high horsepower and high boost Subaru EJ Series engines. This solution is loosely derived from diesel...

The IAG Performance Cooper ring head gasket is manufactured from an asbestos-free composite raw material and features silicone based beading applied to critical areas to improve sealing around all water and oil passages. What sets this gasket apart from...

The IAG Copper O-Ring Wire & Install Tool Kit is intended for use with our case halves or short blocks. The kit includes (4) lengths of copper o-ring wire and a wooden tool handle end intended to press the o-ring wire into the machined groove without...

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: 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 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 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 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...

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 2 Pocket Ported Heads with GSC S2 Cams 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...

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 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 & 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 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 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'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 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 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 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...