Because now that's a thing you know exists.
Up until only very recently, Chrysler's 426 HEMI engine was one which offered almost unheard-of levels of performance for a factory stock V8. People have still used all manner of methods to extract even more power out of them, although one we've never even heard of is to convert it to diesel. Well, we hadn't heard of it before today. Because that's exactly what you'll see in this video. The conversion required custom-machined heads and all new pistons.
The dyno in the video couldn't handle the power of this oddity, but it's said to be turning out somewhere around 2,500 horsepower.