Stage 3 Pocket Ported Heads w/+1mm GSC Valves S20 Casting(Cams/Lifters Sold Sep) 2013-subaru-impreza-wrx sti which cuts the aluminum to

which cuts the aluminum to a smooth

IAG offers our V2 Oil Pickup

Protect the underside of your engine from rocks and debris both on-road and off

the heads are reassembled using GSC Billet S2 camshafts intended for vehicles making 500+ wheel horsepower

the cams are matched to GSC Beehive Valve Springs and Retainers and GSC Viton stem seals then bench-lashed to a tolerance that is close to final specifications

Stage 3 Pocket Ported Heads w/+1mm GSC Valves S20 Casting(Cams/Lifters Sold Sep) 2013-subaru-impreza-wrx sti which cuts the aluminum toIAG 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 S20 head castings,