skip to Main Content
Surgeline Logo

IAG / Willall Billet Aluminum EJ25 Subaru Case Halves For WRX | STI | Forester XT & Legacy GT


IAG / Willall Billet Aluminum EJ25 Subaru Case Halves For WRX | STI | Forester XT & Legacy GT

  • Weight: 0 lb
  • Dimensions: N/A
  • Installation Difficulty:
SKU: IAG-ENG-1600 Categories: , ,


Using the same world-leading technology found in Willall?s incredible billet GT-R block the billet EJ case seeks to change the Subaru performance tuning market by reinventing the EJ and addressing virtually every weakness that exists in max-power builds. 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 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.e. AC/PS/etc.) Multiple Times stiffer and stronger than the stock case Precision machined for a superior surface finish Hard anodized to avoid marking or straining Additional Options: Bore & Hone: Bore & Hone to customer specification $300 O-Ring: O-Ring Deck $200 Case Bolts: ARP Case Bolts $450 Head Studs: IAG / ARP 14mm Head Studs nuts and washers – $550. *14mm head studs are required for this block Minimum Requirements To Build & Assemble: ARP Case Bolts (Sold separately) 14mm Head Studs (Sold separately) Internal components (Pistons Rods Bearings Crank All sold separately). *Attention: Special note about using ARP Case Bolts – IAG installs ARP CASE BOLTS with 30W engine oil using OEM SUBARU torque specs and procedures. Other torque specs and lubricants may lead to case distortion damage.

Make Model Submodel Year
Subaru Forester XT 2004 - 2013
Subaru Impreza WRX 2002 - 2014
Subaru Impreza WRX STI 2004 - 2014
Subaru Legacy GT 2005 - 2009
Subaru WRX STI 2015 - 2018
Close search