Custom-Built Horsepower That Fits You, Not the Masses.

Why a Custom Engine is the Smarter Choice than a Crate Engine?

Crate engines are designed for mass appeal—not performance or driveability.

They’re built to cover a wide range of vehicles and use cases, which means compromises in cam profile, compression, timing, and airflow. That “drop-in and go” convenience can come at the cost of power, drivability, and long-term reliability—especially if your build isn’t bone-stock.

At Box Performance Inc., every custom engine is built to match your setup and expectations.

Here’s where crate engines fall short—and where we take over:

Generic Tuning:

Custom engines are tuned to your combo—fuel type, gearing, altitude, and intended use.

Crate engines ship with conservative tunes and safe compression ratios to avoid issues in unknown vehicles. That means leaving horsepower on the table.

Parts Compatibility:

We factor in your full drivetrain, so everything works together seamlessly.

Crate engines can create mismatches with your transmission, torque converter, or rear-end gear ratio, leading to poor street manners or performance dips.

Assembly Shortcuts:

We use name-brand components and apply blueprint-level clearances to ensure and make any necessary adjustments for your car.

Some crate engines are built to hit a price point, not a performance standard—so you may get unbranded components, factory-style clearances, or other cost cuts.

No Testing:

We live-run every custom engine on a test stand to check oil pressure, timing, temps, and leaks.

Most crate engines aren’t run before shipping. If there’s a problem, you find out the hard way.

No Real Support:

With Box Performance Inc., you’re talking directly to the builders. No script. No guesswork.

With a crate engine, your only help is a generic manual or a support line that doesn’t know your car.

A crate engine is built to fit the average build. We don’t do average. We build for your car—and your goals.