Subaru B25 Cylinder Heads 2.5L Turbo New Castings Refresh & Load Service

Subaru B25 New Castings Refresh & Load Service

Don’t trust your high-dollar internals to a 20-year-old cracked casting.

If you’ve suffered the dreaded spark plug hole crack or your original B25 heads have been surfaced one too many times, we have the solution. Ship us your current B25 cylinder heads, and we will transfer your usable performance internals—valves, springs, retainers, and cams—into brand-new, zero-mile B25 castings.

Eliminate heat stress and warped decks with fresh metal built to professional standards at our precision machine shop.

What’s Included in the Service:

• Brand New B25 Castings (Pair): Single AVCS (Fits ’04–’06 STI, FXT, and others).

• Precision Valve Grinding: We don’t just “lap” old parts. We cut your supplied valves fresh on our professional grinder to ensure a perfect 45° seat and maximum seal.

• Ultrasonic Cleaning & Inspection: All supplied valvetrain components are cleaned and mic’d to ensure they are within spec before assembly.

• Expert Tipping & Assembly: We precision-tip your valves to match the new casting geometry perfectly.

• Professional Lash Setting: All heads arrive fully assembled, lashed, and bench-checked. They are ready to bolt onto your block—no bucket-shuffling or grinding required.

• New Viton Valve Stem Seals: High-temp seals included with every build.

The “OEM Plus” Upgrade Option 

For the enthusiast, we also offer upgraded BC1600-1 Springs to be loaded into your new castings. These single springs are engineered by PAC Racing for consistent pressure and high-RPM reliability—ideal for street-strip builds running 20-25 psi.

BC1600-1 Spring Specs:

The Process:

Purchase: Order the service through our secure checkout.

Shipping Labels: Upon purchase, we will contact you directly with UPS Prepaid shipping labels. Simply box your cylinder heads and drop them off.

The Build: We machine your valves, inspect your parts, load them into the new castings, and perform precision tipping, shimming, and camshaft installation.

Receive: We ship your brand-new, fully loaded heads back to you, ready for immediate installation.

Service Requirements & Terms:

• Required Components: Send in your heads complete with all valves, springs, retainers, keepers, camshafts, camshaft caps/bolts, and buckets.

• Camshaft Condition: Supplied camshafts must be free of damage, scoring, or excessive wear.

• What NOT to Send: Please remove and keep your camshaft sprockets (gears), AVCS phasers, and sensors. You will need these for your final engine assembly.

The “Heavy Duty” Guarantee

We specialize in high-performance automotive machining. We know these heads inside and out. Every set is vacuum-tested to ensure a perfect seat and seal before it leaves our bench.

What Our Customers Are Saying

“Saved my build.” “I was about to buy a used set of heads off a forum until I found this service. Sending my GSC internals and cams to a shop that actually knows how to set Subaru lash correctly was a no-brainer. They sent me the UPS labels the same day I ordered, and the heads came back looking better than factory. Bolted them on and the car is quiet and making 24psi without a hiccup. Highly recommend if you’re tired of cracked B25 castings.” — Chris M., WRX STI Owner

“True OEM Plus quality.” “Finding a machine shop that understands precision tipping and shimming for these heads is rare. I had them load the BC1600-1 springs with my existing valves into the new castings. The turn-around was exactly as promised, and not having to spend hours shuffling buckets myself saved me a huge headache. The engine feels solid and the peace of mind knowing I have zero-mile castings is worth every penny.” — David R., Forester XT Project