Stage 4 CNC Ported Cylinder Head Package for 15-20 WRX AW20 Castings (Cams / Rockers / Lash Caps Sold Separately). 2001-subaru-outback-base Case Features: Machined from solid

Case Features: Machined from solid billet 6061-T6 Aerospace grade aluminum Darton Ductile iron sleeves Increased material thickness in all known weak points (around head studs

the heads are reassembled using GSC Billet S2 camshafts that are intended for vehicles making 500-700 wheel horsepower

GTIN: 00887753779717

Noticeably improved engine response and acceleration

The fitting ties the AOS to the PCV system

Stage 4 CNC Ported Cylinder Head Package for 15-20 WRX AW20 Castings (Cams / Rockers / Lash Caps Sold Separately). 2001-subaru-outback-base Case Features: Machined from solidIAG'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 Subarus. The ported head package starts with brand new AW20 WRX OEM head castings directly from Subaru of America. The bare castings are visually inspected and the OEM guides are pressed out. The heads are then fixtured into our in house Centroid 5 axis CNC