Stage 4 CNC Ported Cylinder Head Package for 15-20 WRX AW20 Castings (Cams / Rockers / Lash Caps Sold Separately). 2001-subaru-outback-base The unique inserts feature small

The unique inserts feature small passages that allow needed coolant flow to the deck surface

All Mishimoto fan shrouds are significantly lighter than standard fan shrouds

0L S20 head castings directly from Subaru of America

Replaces the OEM plastic bracket which is known to break

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

Stage 4 CNC Ported Cylinder Head Package for 15-20 WRX AW20 Castings (Cams / Rockers / Lash Caps Sold Separately). 2001-subaru-outback-base The unique inserts feature smallIAG'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