IAG 600 FA20 DIT Long Block Engine w/ IAG 600 Heads for 2015-21 Subaru WRX

Part Details:

The IAG 600 FA20 DIT Long Block Engine with IAG 600 Heads is a complete, performance-built long block designed for 2015–2021 Subaru WRX models equipped with the FA20 DIT engine. Built to support builds targeting up to 600 BHP, this package pairs IAG’s forged-internal 600 short block with fully assembled IAG 600 cylinder heads to provide a strong, dependable foundation for tuned street cars and moderate turbo upgrades.

If you want a single, ready-to-install long block solution rather than sourcing a short block, heads, and valvetrain separately, this engine package delivers improved durability under boost while maintaining drivability for performance street use.

Vehicle Fitment Overview

Designed for Subaru WRX models equipped with the FA20 DIT engine. Full year-by-year compatibility is listed in the Vehicle Fitment tab above.

This is a performance long block, not a stock replacement. Vehicle configuration, emissions requirements, supporting modifications, and overall build goals should always be verified prior to purchase.

What This Long Block Includes

This is a complete long block assembly that includes the short block and fully assembled cylinder heads, along with the gaskets, hardware, and OEM components listed below (including OEM timing components and OEM oil pump/timing cover as listed).

Important Notes: What’s Not Included

• Intake manifold
• Turbocharger and turbo system components
• Fuel injectors and fuel system components
• Accessory components (alternator, A/C compressor, etc.)
• ECU calibration (tuning)

Power & Build Expectations

• Rated for builds targeting up to 600 BHP
• Final power capability depends on turbo system, fueling, cooling, and tuning quality
• Professional installation is strongly recommended
• ECU tuning is required

IAG 600 FA20 DIT Short Block

• Brand-new OEM Subaru FA20 case halves, bored and honed to 86.1mm
• Case machining modified for improved oiling
• IAG-spec 86.1mm forged pistons with ring set
• 0.150″ x 2.250″ carbon steel wrist pins
• IAG-spec H-beam connecting rods with ARP2000 rod bolts
• ACL or King XPG rod bearings
• ACL or King XPG main bearings
• New OEM Subaru FA20 DIT WRX crankshaft
• OEM Subaru case and main bolts
• OEM oil plug pre-installed at the oil pan location

Compression Ratio

• 10.6:1 compression ratio with standard head gasket thickness

IAG 600 FA20 DIT Cylinder Heads

• Brand-new Subaru OEM WRX AW cylinder head castings
• GSC 36mm intake valves (standard)
• GSC 32mm exhaust valves (standard)
• Kelford dual valve springs with titanium retainers
• OEM valve guides
• GSC valve stem seals
• OEM Subaru lifters
• OEM Subaru rocker arms
• Kelford 264-EZ camshafts
• OEM Subaru lash caps
• Multi-angle valve job
• Resurfacing, ultrasonic cleaning, final lash set

Gaskets, Hardware & Accessories

• ARP 2000 11mm head stud set
• OEM head gaskets
• OEM valve cover gaskets
• OEM valve covers
• OEM timing components
• OEM oil pump and timing cover
• Rear main seal and separator kit
• Crankshaft woodruff key

Installation & Build Notes

• Designed for tuned street builds and moderate turbo upgrades
• Supporting modifications (fueling, turbo system, cooling) should match your power goals
• Break-in procedures and oil selection should follow engine builder recommendations
• Final results depend on the complete setup and professional tuning

Recommended Supporting Upgrades

• Air / Oil Separator (AOS)– helps reduce oil vapor ingestion and protect the intake system
• Oil pickup and baffle upgrades – improves oil control and reduces bearing failure risk
• Long block installation kits – simplifies installation with required gaskets and hardware
• Engine installation fluid kits – includes break-in oil and coolant for first startup

Learn more about IAG Performance engine and reliability solutions