IAG Stage 4 CNC Ported Chamber Matched Heads w/ +1mm GSC Valves & GSC S2 Camshafts for 02-05 WRX 2.0L S20. 1996-subaru-legacy-outback Threads are rolled into the

Threads are rolled into the block rather than conventionally cut for much greater strength

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

The ported head package starts with brand new S20 OEM WRX head castings directly from Subaru of America

Pedders Urethane Lower Control Arm Front Bush (2 PKT) 08-13 Subaru Forester / 07-11 Impreza

IAG Stage 4 CNC Ported Chamber Matched Heads w/ +1mm GSC Valves & GSC S2 Camshafts for 02-05 WRX 2.0L S20. 1996-subaru-legacy-outback Threads are rolled into theIAG Stage 4 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 5 years and tested on the most successful high horsepower Subarus. The ported head package starts with brand new S20 WRX OEM head castings directly from Subaru. The castings are visually inspected then fixtured into our in house Centroid 5 axis CNC Machine, one of the most advanced