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IAG 550 Closed Deck Long Block w/ Stage 1 Heads 2006-2014 WRX / 2004-2021 STI

SKU IAG-ENG-4005W
Original price $9,499.99 - Original price $9,499.99
Original price
$9,499.99
$9,499.99 - $9,499.99
Current price $9,499.99
Select Version/Year: 2008-2021 STI

The IAG Performance Hand-Built 550 Subaru EJ25 Long Block Packages are a complete, valve cover to valve cover, crate engine. These engines offer significant ease of installation for customers seeking a complete "drop-in" engine package for their Subaru WRX, STI, Forester XT or Legacy GT. The Long Blocks feature a combination of our proven IAG Performance Short Block and Cylinder Head package, along with other race-proven components to complete the assembly. When paired with our Long Block Installation 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 550 package is ideal for clients looking for a long block engine package to support up to 550 BHP applications. The IAG 550 long block features our highly popular Stage 2 short block that utilizes a brand new EJ25 Subaru case, 99.5mm IAG-Spec JE forged pistons, IAG Spec H-Beam connecting rods and OEM STI Crank. The block is then paired up with our IAG Stage 1 Cylinder Head Package which features Subaru WRX STI OEM cylinder head castings and GSC valvetrain components. To complete the package, we add an 11mm ARP 2000 head stud set and all required gaskets for the final valve cover-to-valve cover assembly.

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.


IAG 550 Long Block Engine Includes:

Stage 2 Short Block:

  • Case Halves -Brand new Subaru OEM case halves 99.5mm Stock Bore
  • Pistons -IAG-Spec JE 99.5mm Forged Pistons, Ring Set, .180" Chromoly Steel Pins, Clips, (Perfect Skirt Coating and Offset Wrist Pin)
  • Connecting Rods -IAG Spec H-Beam Rods w/ ARP2000 Rod Bolts
  • Rod / Main Bearings -ACL or King Bearings
  • Crankshaft -Standard New Subaru Nitride Treated 2017+ STI Crankshaft
  • Case / Main Bolts -Standard FHI Subaru case bolts


Stage 1 Heads:

  • Heads - Brand New Subaru OEM WRX STI Cylinder Head Castings
  • Intake Valves - GSC 36mm (Standard) Intake Valves
  • Exhaust Valves - GSC 32mm (Standard) Exhaust Valves
  • Springs / Retainers - GSC Valve Springs & Titanium Retainers
  • Guides - OEM Valve Guides
  • Valve Seals - GSC Valve Stem Seals
  • Lifters - OEM Lifter Buckets
  • Camshafts - GSC Stage 1 Billet Camshafts
  • Multi-Angle Valve Job
  • Machined Cam Lobe Clearance
  • Resurface
  • Ultrasonic Cleaning
  • Final Lash


Gaskets, Hardware & Accessories:

  • Head Studs - ARP 2000 11mm Set
  • Head Gaskets - OEM
  • Valve Cover Gaskets - OEM
  • Cam Seals - OEM
  • Valve Covers - OEM
  • Wrist Pin Seal, Rear Main Seal & Separator Kit
  • Crankshaft Woodruff Key



Power:The IAG 550 Long Block has a power output rating of 550BHP.

*All IAG short blocks are balanced and blueprinted.