IAG Stage 4 CNC Ported Heads w/ +1mm GSC Valves for 02-05 WRX 2.0L S20 w/ Chamber Matching(Cams / Lifters Sold Separately). 2020-subaru-wrx sti-sti The modified case halves are

The modified case halves are then measured and assembled using a new FA20 WRX / BRZ Subaru crankshaft that is matched to King main bearings

The 75A durometer bushings reduce the motor movement under hard acceleration

Our test cars serve as daily drivers

IAG 900 EJ25 Closed Deck Long Block w/ Stage 4 Heads: The IAG Performance Hand-Built Subaru EJ25 Closed Deck Long Block Engine Packages are a complete

IAG Stage 4 CNC Ported Heads w/ +1mm GSC Valves for 02-05 WRX 2.0L S20 w/ Chamber Matching(Cams / Lifters Sold Separately). 2020-subaru-wrx sti-sti The modified case halves areIAG 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 Subarus. The ported head package starts with brand new WRX OEM 2. 0L S20 head castings directly from Subaru of America. The bare castings are visually inspected then fixtured into our in house Centroid 5 axis CNC Machine,