IAG Stage 4 CNC Ported Heads w/ +1mm GSC Valves 07 STI V25 Casting (Cams / Lifters Sold Separately). 2011-subaru-impreza-wrx Replaces OEM header hardware

Replaces OEM header hardware

thus reducing aeration

2003-2004 Subaru Forester 2

Compression Ratio: 8

bottom end location) Unique 4 bolt bottom end strengthening Threads are rolled into the block rather than conventionally cut for much greater strength Full cooling system operation Radiused coolant and oil galleries for improved flow and less foaming/turbulence Fits all factory engine bay ancillaries (i

IAG Stage 4 CNC Ported Heads w/ +1mm GSC Valves 07 STI V25 Casting (Cams / Lifters Sold Separately). 2011-subaru-impreza-wrx Replaces OEM header hardwareIAG's Stage 4 Cylinder Head Package utilizes a CNC porting program for the V25 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 STI V25 OEM head castings directly from Subaru of America. The bare castings are visually inspected then fixtured into our in house Centroid 5 axis CNC Machine, one of the most advanced precision engine machining