IAG Performance 550 Series EJ25 Long Block w/ IAG 550 Heads 2002-2014 WRX / 2004-2021 STI / 2004-2013 Forester XT / 2005-2009 Legacy GT

Here, you are looking at the IAG 550 EJ25 Long Block Engine.

A "DROP-IN" SOLUTION
The IAG Performance Hand-Built 550 Subaru EJ25 Long Block Packages are a complete, valve cover-to-valve cover, crate engine. These long block 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 550 Performance Short Block and IAG 550 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.

BUILT WITH 100% NEW COMPONENTSThe 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 IAG 550 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 550 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 550 EJ25 2.5L SUBARU SHORT BLOCK DETAILS

DESIGNED FOR STRENGTH
The IAG 550 Short Block is designed for modified EJ25 Subarus that need a stronger short block to support increased cylinder pressures created by additional boost pressure. The IAG 550 short block features IAG Spec H-Beam forged connecting rods. The upgraded connecting rods and race bearings are able to support additional engine load produced by larger turbochargers or increased boost which the OEM STI rods found in the Stock short blocks cannot support reliably.

BUILT WITH 100% NEW COMPONENTS
Each IAG 550 Short Block starts with brand new EJ25 Subaru 2.5L, 99.5mm stock bore engine case halves as standard. The case haves are carefully measured and assembled using a new 2017+ Subaru 2.5L nitride-treated STI crankshaft, which is matched to ACL or King race main bearings. The IAG 550 Short Block features IAG Spec H-Beam Connecting Rods with ARP2000 rod bolts, along with ACL or King race rod bearings. The case halves are sealed with new OEM main case bolts and sealant. Finally, IAG Spec JE 99.5mm Forged Pistons are carefully selected, measured, and installed to finish off the short block.

FORGED PISTONS, DESIGNED FOR BOOST
Each IAG 550 Short Block features IAG Spec JE 99.5mm Forged Pistons. These 2618 T6 Alloy high-strength pistons have been specifically designed to support increased cylinder pressures which come with more boost. This is accomplished by using an asymmetrical skirt design instead of the traditional full-round skirt, which also reduces weight significantly. Featuring smooth-flowing radii on the domes and dishes, the design promotes excellent flame travel. The pistons are secured to the rods with .905 x 2.250" x .180" wall carbon steel wrist pins with Tru Arc locks.

IAG 550 STREET CYLINDER HEADS PACKAGE DETAILS

ENTRY-LEVEL STOCK REPLACEMENT HEADS
The IAG 550 Cylinder Heads are designed to function as an entry-level replacement for stock OEM heads. If your engine has suffered a catastrophic failure that requires the replacement of your cylinder heads, or if you don't have OEM heads to start with, the IAG 550 Cylinder Heads are a perfect solution. These heads also work great for cars with basic bolt-on parts up to 550 BHP. These heads include upgraded GSC standard-size valves, GSC Viton Valve Stem Seals, IAG Stage 1 Valve Springs with Titanium Retainers, and OEM Keepers. GSC S1 Camshafts are available with OEM valve lifter buckets.

BUILT WITH 100% NEW COMPONENTS
Each IAG 550 Cylinder Head Set starts with new OEM castings from Subaru of America. The first step is to select the Year and Model of the vehicle so that we may provide you with the right castings to fit your project. Next, you'll select whether or not you want to include our optional GSC camshaft package. If selected, these heads will include new GSC S1 Camshafts and OEM Lifter Buckets for valve adjustment.

The bare castings are visually inspected and then fixtured into our in-house Centroid 5-axis CNC Machine. In the Centroid, the heads undergo a cam clearance machining process which removes material from the lifter area where larger lift and duration cam profiles are known to contact the castings. (Just in case you want to go bigger later.) Then the heads are fixtured in our Newen Valve Guide and Seat Machine to cut all intake and exhaust seats with a multi-angle valve job that suits the flow characteristics of GSC's standard size 36mm Intake and 32mm Exhaust valves. At this point, the heads' decks are resurfaced using our TS-3000 BlockMate, which cuts the aluminum to a smooth, even finish. Next, the heads are ultrasonically cleaned to remove debris and oils from the machining process. Finally, the heads are reassembled using GSC Stainless Intake and Exhaust Valves, GSC Viton stem seals, IAG-Stage 1 Valve Springs with Titanium Retainers, and OEM Valve Keepers.

GSC S1 CAMSHAFT AND LIFTER BUCKET PACKAGE
The included GSC Power-Division billet S1 camshafts for your IAG 550 Head Package will not drop any low-end power, and will create more power and torque across the entire RPM range. These are perfect for stock frame upgraded turbos or up to 500 WHP upgrades. Along with the camshafts, we'll include all new OEM valve lifter buckets and set the final lash

IAG 550 EJ25 2.5L LONG BLOCK INCLUDES

IAG 550 EJ25 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
• IAG 550 Cylinder 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 Rating: The IAG 550 Long Block has a power output rating of 550 BHP.

IAG stands behind every hand-built engine they produce. IAG's Standard Long Block Workmanship Warranty covers your long block for 12 months or 12,000 miles. IAG has also teamed up with a selection of IAG Certified Installation Facilities which offer up to a 24-month/24,000-mile workmanship warranty when the engine is purchased, installed, and tuned by that IAG Certified Installer.