What Does It Take To Get 300 HP Out Of A Bone Stock 7.3-Liter? The KC Turbos Crew Set Out To Find Out.

Driving a stock 7.3-liter Power Stroke often feels sluggish compared to modern diesel platforms. These older trucks rolled off the assembly line with conservative power figures that leave current enthusiasts wanting more.

We already covered this heavy iron block before, but now, can it actually hit 300 horsepower without tearing into the internal components?

Cameron Lewis of KC Turbos partnered with his friend Ben Hess to answer that question by strapping modern air upgrades onto an old body style Ford pickup.

Uncovering The Hidden Calibration

Before wrenching on the engine, the crew needed a true baseline. Ben originally thought his truck ran a factory calibration. Pulling the powertrain control module out of the fender wall revealed a surprise.

A Banks Big Hoss module sat attached to the computer. Ben drove the truck with a newly installed Hydra tuner set to the factory calibration to feel the baseline power level.

He states, “I do feel the difference. This is not as fun.” The heavy pickup required aggressive throttle input just to accelerate normally.

Wrenching On A Stock 7.3-liter

Removing the original turbocharger turned into a miserable four-hour ordeal. They fought rusted hardware on the factory flange, eventually snapping bolts and splitting a seized nut with an air hammer.

Decades of worn cab mounts and sagging engine mounts made aligning the exhaust piping difficult.

Cameron explains, “As you guys saw, this is frustrating. Working on an OBS is tough. These trucks are like 30 years old.” To simplify the installation, they bolted the driver-side exhaust pipe first before tightening the passenger-side collector.

Hitting The Dyno Rollers

Lewis then dropped a Gen 3 KC300X conversion kit onto the engine. This modern hardware eliminates the restrictive factory flange, making future maintenance much easier.

Then they removed the aftermarket air filter to eliminate any intake restriction before securing the truck to the dyno. The diesel generated an impressive 284 horsepower on original factory injectors.

This output exceeded initial expectations for an old motor breathing through factory fueling components.

Final Output Thoughts

Pushing a stock 7.3-liter to near the 300 horsepower mark proves how much air these old blocks actually need. Swapping out the restrictive factory turbocharger completely changes the driving dynamic.

Both of them are now planning to add larger injectors and an upgraded oil pump to chase 450 horsepower.