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IAG Performance 900 Long Block 900 Closed Deck Long Block Engine w/ Stage 4 Heads & GSC S2 Cams

Engine Long Block


IAG 900 Closed Deck Long Block Engine w/ Stage 4 Heads & GSC S2 Cams for 04-07 STI.

  • These engines offer significant ease of installation for customers seeking a complete "drop-in" engine package for their WRX, STI, Forester XT or Legacy GT.
Pricing: $12,749.99

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


Subaru: Legacy 05 - 06, Subaru: Impreza 04 - 07, Subaru: Forester 04 - 05

  • All IAG Longs Blocks are crated and shipped by freight trucks which include lift gate service.
  • All IAG short blocks are balanced and blueprinted.
  • IAG 900 Long Block Engine Includes: IAG Magnum Closed Deck Short Block: Case Halves - Converted to Closed Deck using brand new Subaru OEM case halves, bored and honed to 99.75mm. 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 Head Studs - Machine Case for 14mm head studs Pistons - IAG-Spec JE FSR 99.75mm 2618 Forged Pistons, Electroless Nickel Plated Tops & Ring area, Ring Set, .250" / .906" H13 Wrist Pins, Clips, (Perfect Skirt Coating and Offset Wrist Pins) Connecting Rods - IAG-Spec Tuff H-Beam +2mm / ARP 625+ Rod Bolts. Rod / Main Bearings - ACL or King Race bearings. Crankshaft - Standard New Subaru Nitride Treated 2017+ STI Crankshaft. Case / Main Bolts & Standard FHI Subaru case bolts. Stage 4 Heads: Heads - Brand New Subaru OEM WRX STI Cylinder Head Castings Machine Porting - CNC Ported Intake and Exhaust Runners Intake Valves - GSC 37mm (+1mm) Intake Valves Exhaust Valves - GSC 33mm (+1mm) SuperAlloy Exhaust Valves Springs / Retainers - GSC Beehive Valve Springs & Retainers Guides - GSC Maganese Valve Guides Valve Seals - GSC Valve Stem Seals Lifters - OEM Lifter Buckets Camshafts - GSC Stage 2 Billet Camshafts, Multi-Angle Valve Job, Machined Cam Lobe Clearance, Drilled For 14mm Heads Studs, Ultrasonic Cleaning, Final Lash Gaskets, Hardware & Accessories: Head Studs - IAG / ARP 14mm Set Head Gaskets - IAG Fire-Lock, Valve Cover Gaskets - OEM, Cam Seals - OEM, Valve Covers - OEM, Wrist Pin Seal, Rear Main Seal & Separator Kit, Crankshaft Woodruff Key
  • IAG's Break-in Instructions MUST be followed, and the long block must be professionally installed for the 12 month/12,000 mile workmanship warranty to be applicable. If the previous engine experienced an internal failure then all oiling components (i.e. cooler, pump, pickup, cam gears, and solenoids, etc) as well as other necessary components as per your installer's recommendations, must be replaced during installation.
  • Please review the PDF document below regarding installation, break-in procedures and warranty information.
  • Power: The IAG 900 Long Block has a power output rating of 900BHP.

IAG 900 EJ25 Closed Deck Long Block w/ Stage 4 Heads: The IAG Performance Hand-Built Subaru EJ25 Closed Deck Long Block Engine Packages are a complete, valve cover to valve cover, crate engine. These engines offer easy installation for customers seeking a complete "drop-in" engine package for their WRX, STI, Forester XT or Legacy GT. The Long Blocks feature a combo of our proven IAG Performance Closed Deck Short Block and Cylinder Head packages, along with other race-proven components to complete the assembly. When paired with our Long Block Install Packages, you have a true plug-and-play solution to get you back on the road, FAST! All components included are BRAND NEW and there is NEVER A CORE CHARGE required. The IAG 900 package is ideal for clients looking for an engine package to support up to 900 BHP. The IAG 900 Long Block features our Magnum Closed Deck Short Block that utilizes a brand new EJ25 Subaru case that is converted to closed deck and is bored and honed to 99.75mm. The Magnum block features 14mm head stud machining, as well as our Fire-Lock gasket solution. The combination of the alloy compression shims and gaskets in the Fire-Lock system assure maximum sealing for a Subaru EJ25 turbocharged engine. The Magnum internals includes IAG-Spec JE FSR 2618 forged pistons, .250" / .906" H13 pins, IAG-Spec Tuff H-Beam +2mm connecting rods with ARP 625+ rods bolts and an OEM STI crankshaft. The block is then paired up with our Stage 4 Fully CNC Ported Cylinder Heads to deliver maximum flow for high hp applications. The heads start as new Subaru OEM castings that are CNC machined and resurfaced. The heads are outfitted with GSC valve train components including +1mm oversized intake and SuperAlloy exhaust valves, Beehive Springs and GSC Billet Stage 2 camshafts. To complete the package, we add an IAG / ARP 14mm head stud set and all the required gaskets for the final valve cover-to-valve cover assembly.


  • IAG-ENG-4025VS2
  • IAG-ENG-4025VS2
  • 887753778949
  • IAG Performance
  • New


Shipping Information

  • Item Requires Shipping
  • 285.0 lbs.
  • W32.0000” x H28.0000” x L46.0000”
  • Free ground shipping on all order over $100.00 (some exclusions may apply)

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