IAG 950 2.35L DESTROKED LONG BLOCK ENGINE W/ IAG 950 HEADS

IAG 950 2.35L Destroked Long Block Engine for Subaru 02-14 WRX, 04-21 STI, 04-13 FXT, 05-09 LGT

DROP IN AND DRIVE

The IAG Performance hand-built Subaru 950 2.35L Destroked Long Block Engine package is a complete, valve cover-to-valve cover crate engine. Designed as a true drop-in solution, this long block is ideal for 2002–2014 Subaru WRX, 2004–2021 Subaru STI, 2004–2013 Subaru FXT, and 2005–2009 Subaru LGT applications.

This package combines our proven IAG EJ25 2.35L Destroked Closed Deck Short Block with IAG 950 CNC Ported Cylinder Heads and a full selection of high-performance components. When paired with our Long Block Installation Packages, you’ll have a plug-and-play solution to get you back on the road fast. All components are BRAND NEW and there is NEVER a core charge.

HAND-BUILT WITH 100% NEW COMPONENTS

Designed for extreme performance applications, the IAG 950 2.35L Destroked Long Block supports up to 950 BHP. The foundation begins with a brand new Subaru EJ25 case converted to a closed deck configuration and bored and honed to 99.75mm.

This block features 14mm head stud machining and IAG’s proprietary Fire-Lock™ head gasket system, providing unmatched sealing strength under high boost. Internal components include custom JE 99.75mm FSR 2618 pistons with JE Pro Seal rings, .240" H13 tool steel wrist pins, custom IAG-spec +2mm H-beam forged connecting rods with ARP 625+ bolts, a 2.0L FHI crankshaft, ACL race bearings, and OEM Subaru case bolts.

The block is paired with IAG 950 Fully CNC Ported Cylinder Heads featuring GSC valvetrain components, +1mm oversized valves, IAG beehive valve springs, GSC Stage 2 camshafts, and Kelford DLC-coated lifter buckets. Final assembly includes an IAG / ARP 14mm head stud set and all required gaskets for a complete valve cover-to-valve cover solution.

IAG 950 EJ25 2.35L DESTROKED CLOSED DECK SHORT BLOCK

THE ULTIMATE WEEKEND RACER

The IAG 950 2.35L Destroked Closed Deck Short Block delivers track-level performance while maintaining the reliability needed for street use. Supporting up to 950 BHP, this short block utilizes a 2.0L FHI crankshaft, IAG-spec +2mm forged H-beam rods with ARP 625+ bolts, and JE 99.75mm FSR 2618 pistons treated with electroless nickel plating for increased durability and detonation resistance.

DESTROKED FOR HIGH-REVVING APPLICATIONS

The destroked configuration reduces piston speed, improves rod-to-stroke ratio, and increases piston dwell time at top dead center. These benefits result in improved combustion efficiency, reduced stress at high RPM, extended ring life, and the ability to safely rev to 8,500 RPM—making this setup ideal for track days, rally, drag racing, and high-performance street builds.

CLOSED DECK WITH 100% NEW COMPONENTS

Each short block begins with brand new Subaru EJ25 case halves, CNC machined in-house to accept IAG Closed Deck inserts. The case is then bored and honed to 99.75mm using deck plates to ensure precise piston-to-wall clearances. Fire-Lock™ receiver grooves are machined into each cylinder and the case is drilled for 14mm head studs before final assembly.

IAG FIRE-LOCK™ SYSTEM

IAG’s Fire-Lock™ system separates combustion sealing from oil and coolant sealing, creating the strongest Subaru head gasket solution available. Precision-machined receiver grooves accept stainless fire rings that protrude above the deck surface, ensuring superior sealing even under extreme boost and cylinder pressure.

IAG 950 CNC PORTED RACE CYLINDER HEADS

BUILT WITH RACING IN MIND

The IAG 950 CNC Ported Race Cylinder Heads are designed for competitive racing environments and support up to 950 BHP with proper supporting modifications. These heads offer significantly increased airflow over IAG 750 heads and are ideal for drag racing, time attack, hill climb, and high-horsepower builds.

PRECISION CNC PORTING

Each head begins as a brand new OEM Subaru WRX STI casting and is CNC ported on our in-house Centroid 5-axis machine. This process ensures consistent, repeatable airflow improvements that are difficult to achieve with hand porting. Additional machining includes cam clearance modification, 14mm head stud drilling, multi-angle valve jobs, resurfacing, and ultrasonic cleaning before final assembly.

GSC STAGE 2 CAMSHAFT PACKAGE

To maximize performance, the IAG 950 heads are equipped with GSC Power-Division Stage 2 billet camshafts and Kelford DLC-coated lifter buckets. Designed for builds producing 500 WHP and beyond, these cams unlock the full potential of the CNC ported heads when paired with proper fueling, turbocharging, and engine management.

IAG 950 EJ25 2.35L LONG BLOCK INCLUDES

IAG 950 EJ25 2.35L Short Block:

• Brand new Subaru OEM EJ25 case halves
• IAG Fire-Lock™ receiver groove machining
• JE 99.75mm FSR 2618 custom pistons with JE Pro Seal rings
• .240" H13 tool steel wrist pins
• IAG-spec +2mm forged H-beam connecting rods with ARP 625+ bolts
• ACL race rod and main bearings
• 2.0L FHI crankshaft
• Standard Subaru case bolts

IAG 950 CNC Ported Cylinder Heads:

• New OEM Subaru WRX STI cylinder head castings
• CNC ported intake and exhaust runners
• GSC +1mm intake and exhaust valves
• IAG-spec beehive valve springs with retainers
• GSC manganese valve guides
• Kelford DLC-coated lifter buckets
• GSC Stage 2 billet camshafts
• Multi-angle valve job
• 14mm head stud machining
• Final lash adjustment

Gaskets, Hardware & Accessories:

• IAG / ARP 14mm head stud set
• IAG Fire-Lock™ head gaskets
• OEM valve cover gaskets
• OEM cam seals
• OEM valve covers
• Rear main seal, wrist pin seals, and separator kit
• Crankshaft woodruff key

Please Note: This item is not eligible for standard ground shipping and must be delivered via freight. 
STOCK NOTICE: This item is built to order and carries a minimum 6-8 week build time.

IMPORTANT DELIVERY NOTE: Your order is shipping Via Truck Freight which requires you to be available at the time of receipt. There is a possibility the trucking company will try to schedule a delivery time with you. At the time of delivery, the driver will hand you the delivery receipt also referred to as the bill of lading, you will use this to notate any damages to the shipment. It is important that you fully inspect the shipment from all sides and notate any dents, punctures or rips in the outside packaging on the delivery receipt. Once you've inspected your shipment from the outside, you will need to open it and check the product in its entirety for damages and notate them if any. If there is no damage sign for the package and enjoy! In the rare case, you do find that your order arrived with damages, it is important you follow these steps. - Do not refuse the product- Document the damages in as much detail as possible on the Bill of Lading
- Take numerous photos from all angles (including packaging)
- Keep the product and contact the shipping company to start the damage claim
- Contact us either by phone or email for the next steps In the situation where the delivery driver is unable to wait for you to open and inspect your product, simply document "driver was unable to wait for inspection." All damage must be noted on the Bill of Lading before signing and initiating a damage claim. If the damage is not notated before signing for the item it is assumed to be in good condition. This will forfeit the ability for a shipping claim and you will not be eligible for refund or replacement.