The CNC Billet Aluminum 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.

Each IAG / Crest CNC Case is machined from 6061-T6 Aerospace Aluminum and features Darton Ductile Iron Sleeves. The block is designed with increased material thickness over the OEM cast aluminum case halves and adds a unique 4-bolt bottom end for additional strength.

The IAG / Crest CNC Stage “X” Block, (Formally Willall) is a complete short block built on the Crest billet platform, which also includes pistons, rods, bearings, crank, bore/hone, case bolts, line hone, and final assembly and blueprinting.

Stage X Billet EJ25 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

IAG Stage X Complete Shortblock Includes:

• Case - WREJBB Billet / Sleeved Case Halves
• Fire-Lock - IAG Fire-Lock receiver groove machining, latest solution to prevent head gasket failure on high horsepower and high boost Subaru's - *IAG Fire-Lock head gaskets required and sold separately
• Machining - Machined for 14mm Head Studs *(Studs sold separately / Note the proper head gaskets or head gasket modifications are required for proper fitment with 14mm studs.
• Pistons – IAG-Spec JE FSR 99.75mm 2618 Forged Pistons, Electro-nickel Plated Tops & Ring area, Ring Set, .250" / .927" H13 Wrist Pins, Clips, (Perfect Skirt Coating and Offset Wrist Pins)
• Connecting Rods – IAG-Spec +2mm Tri-Beam w/ ARP625+ Rod Bolts
• Rod/Main Bearings – ACL/King Race Bearings
• Crankshaft – Manley Billet Crank
• Case / Main Bolts – ARP Main Bolts

Power:

• The IAG Stage X Short Block has a power output rating of 1100+BHP.

Compression Ratio:

• 8.5:1 on D Cylinder Heads (EJ255)
• 8.2:1 on B, V and W EJ257 Heads with standard thickness gasket.

Head Gasket Required:

• IAG Fire-Lock .051" Head Gaskets with IAG-Spec Alloy Ring Set - PN# IAG-ENG-1740

Additional Options Available:

• Head Studs - IAG / ARP Spec 14mm head studs, nuts, and washers required (Sold Separately)
• Oil Pump - Subaru JDM 12mm High Volume Oil Pump or 11mm Subaru Oil Pump (Sold Separately)
• Head Gaskets - IAG Fire-Lock .051" Head Gaskets with IAG-Spec Alloy Ring Set - Required for use with this short block (Sold Separately)
• Hardware/Seals - OEM cover and seal kit (Sold Separately)

Not planning on reusing your original short block service plugs and covers? IAG offers a simple comprehensive cover and seal kit that includes:

• (1) Rear main seal
• (3) OEM wrist pin plugs
• (3) OEM wrist pin plug washers
• (1) OEM separator cover
• (6) OEM separator cover bolts
• (1) OEM wrist pin service cover
• (1) OEM wrist pin service cover O-ring
• (2) OEM wrist pin service cover screws.

If you are reusing your original wrist pin service plugs and covers always replace the following components before installing a short block to avoid potential leaks:

• (3) OEM wrist pin plug washers
• (1) wrist pin service cover O-ring

Never reuse a rear main seal on a new short block.

Note: All IAG Short Blocks are balanced and blueprinted.

Please review the PDF document below regarding installation, break-in procedures and warranty information.