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IAG Performance SX EJ25 Short Block Stage X 2.5L Subaru Billet Aluminum Short Block

Engine Short Block


IAG Performance / Crest Stage X 2.5L Subaru Billet Aluminum Short Block for WRX, STI, LGT, FXT.

  • All IAG short blocks are balanced and blueprinted.
  • Compression Ratio: 8.5:1 on D Cylinder Heads (EJ255) 8.2:1 on B, V and W EJ257 Heads with standard thickness gasket.
  • The IAG / Crest Stage X Short Block has a power output rating of 1100+BHP
Pricing: $17,599.99

Free ground shipping on all order over $100.00 (some exclusions may apply)


Subaru: WRX 12 - 12 STI, Saab: 9-2X 05 - 06 Aero, Subaru: Baja 04 - 06 Turbo, Subaru: Impreza 02 - 14 WRX STI Special Edition / WRX SE / WRX GT / WRX Premium / 2.5 GT / WRX STI Limited / WRX / WRX STI / WRX Limited / WRX TR, Subaru: WRX STI 15 - 21, Subaru: Legacy 05 - 12 2.5GT / GT Limited / GT spec.B / GT, Subaru: Outback 05 - 09 2.5 XT / XT Limited / XT, Subaru: Forester 04 - 13 XT Sports / Sports 2.5 XT / XT Limited / XT Touring / 2.5 XT / XT / XT Premium

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 Subarus - IAG Fire-Lock head gaskets required Machining - Machined for 14mm Head Studs (Studs sold separately / Fire-Lock Head Gaskets are Required. 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 - IAG-Spec Billet Crank, Case / Main Bolts - ARP Main Bolts

IAG / Crest Stage X Billet Aluminum EJ25 Subarushort Block 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. The Stage "X" Block is a complete short block built on the Willall 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-ENG-1611
  • IAG-ENG-1611
  • 887753778178
  • IAG Performance
  • New


Shipping Information

  • Item Requires Shipping
  • 130.0 lbs.
  • W20.0000” x H20.0000” x L20.0000”
  • Free ground shipping on all order over $100.00 (some exclusions may apply)

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