IAG Stage 2 Tuff Short Block 2.5L Subaru WRX / STI / Legacy GT / Forester XT

IAG Performance
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he IAG Stage 2 Tuff short block starts with new Subaru 2.5L EJ25 engine case halves that are bored and honed to 99.75 on our in house Sunnen SV-10. IAG's in house honing process is able to set piston to wall clearances tighter for a quieter running engine. The short block is measured and assembled using a new 2012+ Subaru 2.5L heat-treated STI crankshaft that is matched to ACL Race main bearings. Next Manley H-Tuff forged rods with ARP Rod Bolts are utilized to increase the power rating slightly at the expense of being heavier. The connecting rods are matched to ACL Race rod bearings. The case halves are sealed with new OEM main case bolts and sealant. Finally Manley 99.75mm Platinum Series Forged Pistons are spec'd and installed finishing off the short block. 

The IAG Stage 2 Tuff Short Block has a power output rating of 675BHP.

*All IAG short blocks are balanced and blueprinted.

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

Not planning on reusing your original short block service plugs and covers? IAG offers a simple comprehensive cover and seal kit that includes the (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 and (2) OEM wrist pin service cover screws. *If you are reusing your original wrist pin service plugs and covers always replace the (3) OEM wrist pin plug washers and (1) wrist pin service cover O-ring before installing a short block to avoid potential leaks. 


  • Manley 99.75mm Platinum Series Pistons, Ringset, Tool Steel Pins and Clips (w/ Coated Skirts and Offset Wrist Pin) 
  • IAG Spec Bore and Hone (Performed on our in house Sunnen SV-10) 
  • Tighter piston to wall clearance for quiet operation 
  • New FHI Subaru Case Halves (Bored, Honed and Plateau Brushed) 
  • Manley H-Tuff Forged Connecting Rods w/ ARP Rod Bolts (Heavier Version of H-beam Rods) 
  • New FHI Subaru Heat-Treated 2012+ STI Crankshaft 
  • ACL Race Rod Bearings 
  • ACL Race Main Bearings 
  • New FHI Main Case Bolts 
  • IAG Spec Blueprint Sheet 
  • Power Output Rating: 675BHP


2002-2014 WRX

2004-2017 STI

2005-2012 Legacy GT

2004-2013 Forester XT

***All engines are delivered in a cardboard box from IIR***


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