IAG 500 Long Block Engine w/ W25 Heads

2008-2020 Subaru STI

Ships for free in the 48 states


On order from MFG
Average time to ship: 30 business days

The 500 EJ25 Long Block Engine w/ Stage 1 Heads will hold up to 500 BHP in the Subaru STI. 


IAG 500 EJ25 Long Block Engine w/ Stage 1 Heads

Stage 1 Short Block Specs:

  • Case halves - Brane 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 pins
  • Early OEM (stronger) STI connecting rods
  • Will include ACL or King rod and main bearings
  • New nitride-treated 2017+ STI crankshaft
  • Assembled with new standard FHI Subaru case bolts
  • Wrist pin seal, rear main seal, and separator kit
  • Crankshaft woodruff key
  • Power rating to 500 BHP


Stage 1 Head Specs:

  • Starts with brand new Subaru OEM WRX/STI cylinder head castings
  • GSC 36mm standard intake valves
  • GSC 32mm standard exhaust valves
  • GSC single valve springs and titanium retainers
  • OEM valve guides
  • GSC valve stem seals
  • OEM lifter buckets
  • GSC Stage 1 billet camshafts
  • Multi-angle valve job
  • Machine cam-lobe clearance
  • Resurface
  • Ultrasonic cleaning
  • Final lash
  • ARP 2000 11mm head studs
  • OEM head gaskets
  • OEM valve cover gaskets
  • OEM cam seals
  • OEM valve covers


IAG 500 EJ25 Long Block Engine w/ Stage 1 Heads

The IAG Performance Stage 1 Short Block is a great idea for those of you who want a brand-new replacement motor that has been balanced, blueprinted, and assembled by one of the leaders in the Subaru performance industry. This is a complete valve cover to valve cover assembled long block crate engine that has been assembled with proven performance components to sustain power levels up to 500 BHP.

This is a plug-and-play solution complete with heads, all seals installed, and all bearings properly clearanced and ready to install into your vehicle. All components are brand new with no core charge required. This eliminates the need to have any down

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