Among the many great engines throughout the American automobile industry, the original Ford Flathead V8 ranks amongst the most popular and influential racing engines of all time. Not that Henry Ford had racing in mind when he designed it. But the Flathead would go on to become the engine of choice for hot rodders before, during, and after World War II. Yet they were never designed to make that much horsepower, rated at just 85 ponies from the factory. One of the main drawbacks for the Flathead Ford was its signature feature; the built-in valve system.

Hot rodders quickly found a way around that, creating everything from camshafts to cylinder heads for the ol’ Flathead Ford. Even godfather of the Corvette Zora Arkus-Duntov got in on the Flathead action, designing a unique hemispherical overhead-valve cylinder head conversion kit for Flathead V8’s that infinitely increased their performance potential.

Very few of these original Ardun-conversion cylinder heads were built, estimated at just 50 pairs. Yet even today these cylinder heads are still around, and they have been brought back from the grave twice to satisfy the needs of modern-day hot rodders. It’s an unusual design, removing the flathead from a Flathead Ford V8…but it pays performance dividends.

Just watch this video found by Bangshift of an Ardun-head-equipped hot rod rocking the dyno. This hot rod holds the class record for top speed at over 157 mph. But more impressive is the fact that the Flathead V8 (with Ardun heads) can hit 6,200 RPM and still lay down over 400 horsepower at the wheels. That’s the kind of power the original hot rodders could only dream about.