Subaru Long Block: A Performance Buyer's Guide
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Rod knock. A failed engine. When it's time for a serious overhaul or a major power upgrade, the choice matters. A long block is a nearly complete engine, professionally assembled — a fresh start instead of a pile of parts to piece together. This guide covers what a long block is, when it's the right call, what it costs, and what to check before you buy.
What Is a Subaru Long Block?
A long block is the core of the engine, assembled. Inside the block is the rotating assembly: crankshaft, connecting rods, and pistons. Bolted on top are the cylinder heads with the complete valvetrain — camshafts, valves, springs, and lifters. Everything from the oil pan rail to the valve covers. Because the core components are matched and assembled by the builder, there's no guesswork about whether the top end and bottom end belong together.
Long Block vs. Short Block: What's the Difference?
The difference is the cylinder heads. A short block is the bottom end only: block, crank, rods, and pistons. A long block adds the top end — heads and valvetrain — assembled and matched to the bottom end. Crawford sells both. Which one you should buy depends on the condition of your heads and who's doing the work.
When to Choose a Short Block
A short block makes sense if your original cylinder heads are in excellent condition and you — or a machine shop you trust — have the expertise to inspect, machine, and assemble them onto the new bottom end. You take on the responsibility for component matching, clearances, and final assembly. That requires specialized tools and a real understanding of these engines. It also allows more customization of the top end, if that's what the build calls for.
When a Long Block Is the Better Option
For most owners, the long block is the better buy. The most critical parts are already matched and assembled, which removes the head-to-block compatibility risk and cuts installation time. Reusing old heads to save money can backfire: wear, warping, or compatibility problems in a used head can compromise a brand-new bottom end and lead to premature failure. A long block is one integrated unit, built to work together. That holds whether the car is a high-horsepower STI or a daily driver.
Does Your Subaru Need a New Long Block?
Sometimes the signs are loud. Rod knock is the classic one — a serious internal failure. The quieter signs matter too: excessive oil consumption, a significant loss of power, or low compression in one or more cylinders. The other reason is ambition. If the build will push far beyond what the factory engine can take, a built long block is the foundation that handles it.
The Crawford Line
Every Crawford motor starts from a brand-new OEM block. No core is required or needed — there's no core charge and no used case going back into service. Crawford builds in two lanes: fully built engines, and BTO — Better Than Original. Built long blocks ship free.
The ratings, so you can match the engine to the goal:
- CrawfordSPEC CSS 540 — 450 whp / 540 bhp
- Club Racer CCR 660 — 550 whp / 660 bhp
- Racer Spec CRS 720+ — 600+ whp / 720+ bhp
- FA20 DIT short block — rated 660 hp
The older stage-named EJ blocks — S2 (450 whp), S3L-X (550 whp), and S3L-X FSR (600+ whp) — are legacy engines, named and rated as they were built. CrawfordSPEC pistons are forged by JE Pistons.
Crawford's built EJ long blocks run $6,999 to $8,499, from the CSS 540 to the CRS 720+ — one price per engine, labeled MSRP.
Numbers on a nameplate are a starting point, not the whole decision. What determines an engine's strength is what's inside it: forged pistons and rods, upgraded head studs, and case bolts, matched to the power target. Ask any builder for the full parts list before you pay.
Browse the line: Crawford Performance long blocks.
Will It Fit? Checking Model Compatibility
Verify compatibility before anything else. Match the engine size (2.5L or 2.0L), confirm whether the car is turbocharged or naturally aspirated, and confirm the year range. An engine for a 2015+ WRX will not work in an older STI. Getting this wrong is an expensive way to start a build.
Common Subaru Engine Codes: EJ25 vs. FA20
Two engine families cover most of these cars. The EJ25 powered the 2002–2014 WRX and the 2004–2021 STI — the older platform, with a massive aftermarket behind it. The FA20 DIT is the modern direct-injection turbo engine in the 2015–2021 WRX, with different power delivery and different component compatibility. Know which engine your car has before you shop. It dictates everything downstream.
How Much Does a Subaru Long Block Cost?
Across the aftermarket, a high-quality Subaru long block generally runs $6,999 to $19,500. The lower end covers durable engines for spirited daily driving or moderate track use, built to handle more than a stock motor. The top end buys more extensive modification, higher-grade materials, and components engineered for serious competition — a top-tier build like the Ken Block Spec EJ257 sits around the $12,000 mark. A factory-spec OEM long block typically runs $6,999 to $12,000 and restores stock performance; it is not a performance build.
EJ and FA engines price differently — component design, availability, and the upgrades each platform needs all move the number. So does the goal. A long block built for extreme horsepower costs more than one built for a reliable daily driver, because the internals are different.
The engine is not the whole bill. Budget for an installation kit: timing belt or chain, tensioners, gaskets, seals, and fluids. Reusing old wear parts on a new engine is a false economy — it's how new engines get hurt by old failures.
Price differences between builders come down to the components inside, the precision of the machining and assembly, and what the engine is built to handle. Match the engine's capability — and its price — to how the car will actually be used. Overbuying wastes money. Underbuilding costs more.
What to Look for in a Long Block Warranty
A long block is a major investment, and the warranty is the builder's confidence stated in writing. Read it before you commit — the coverage, the duration, and the conditions.
Crawford's built engines carry a 1-year / 12,000-mile warranty. Two conditions are mandatory: follow the break-in procedure below, and complete the first oil analysis. Break-in compliance and that oil analysis are warranty conditions, not suggestions.
On any builder's warranty, check which parts are covered and which are not. Core coverage is typically the block, cylinder heads, and the rotating assembly — pistons, rods, crankshaft. External components and accessories — intake and exhaust manifolds, turbocharger, fuel injectors, sensors — are typically excluded. Know the distinction before there's a claim. Improper installation, skipped break-in, and wrong fluids are common reasons claims get denied, at any builder.
How to Choose the Right Long Block for Your Subaru
Match the Engine to Your Goals
Define the car's purpose first. A daily driver, an overlanding rig, a weekend drag car, and a dedicated track build each need a different balance of power and reliability. A 400-horsepower street car and a 600-horsepower race engine are built differently inside. Be realistic about the power target and how the car gets driven, and the engine choice gets straightforward. Model-specific parts matter too — start with the parts that fit your car, like the WRX upgrades for the WRX.
What Other Modifications Will You Need?
A long block doesn't work alone. The supporting systems have to match the power: fuel injectors and fuel pump, the turbo, and the cooling system. A professional tune is required — a built engine on a stock or off-the-shelf tune can damage itself, and builders expect the tune as part of validating the build. Budget for the supporting parts from the start, not after the engine is in.
Plan for the wear items the installation touches anyway: a new clutch, water pump, thermostat, and oil cooler are all smart money while the engine is out.
Assess Build Quality — and Get the Parts List
Assembly quality matters as much as the parts. A long block from a reputable builder is an integrated system: heads, camshafts, and valvetrain matched and assembled to specification. Ask for a detailed parts list — every component, from the pistons and rods to the camshafts and valve springs. A builder who provides it is showing you exactly what you're paying for, and it lets you compare builds on equal terms. A builder who won't is telling you something too.
Post-Installation: The Break-In Period
The first miles decide how the engine lives. Break-in seats the piston rings against the cylinder walls, which is what gives you compression, power, and oil control for the life of the motor. Rush it and the damage is permanent — excessive oil consumption and lost performance that don't come back.
Crawford's break-in spec:
- Oil changes at 500 and 1,500 miles
- Keep engine speed between 2,000 and 4,500 RPM, and vary it
- No sustained cruising, and no full-throttle pulls
- Do not exceed 80% of target boost until break-in is complete
- The first oil analysis is mandatory — it's a warranty condition
Questions before you order: (855) 677-8243.
Frequently Asked Questions
Why choose a long block instead of a short block with my old heads? Because the old heads are the risk. Wear, warping, or a compatibility problem in a used head can compromise a new bottom end. A long block arrives as one matched, assembled unit — heads, valvetrain, and bottom end built to work together, with clearances set by the builder.
What else should I budget for? An installation kit (timing components, gaskets, seals, fluids), and the wear items worth replacing while the engine is out: clutch, water pump, thermostat, oil cooler. By power goal: fuel pump, injectors, and turbocharger.
Will a professional tune void the warranty? No — the opposite. A professional tune is a requirement. A built engine's components need precise calibration; running one on a stock tune is how engines get damaged and claims get denied.
Is a more expensive long block always the right choice? No. The right long block is the one matched to your goal and your use. An engine built for 700 horsepower is wasted on a daily driver. Buy the engine that reliably handles your target power level.
How important is break-in, really? It's critical, and it's a warranty condition. Follow the spec above — oil at 500 and 1,500 miles, 2,000–4,500 RPM varied, no sustained cruising or full-throttle pulls, no more than 80% of target boost, and the first oil analysis completed.