The Boss 429, which is the basic inspiration behind the overgrown Kaase version here is one of the neatest engines to ever come out of a Detroit manufacturer. Like the “Cammer” V8s of the 1960s, the life of the Boss 429 was short-lived. Far more fearsome in race trim than on the street, the hemispherically headed Ford engine looked like nothing else when it came out and it had a mystique all of its own.

These engines really make some steam in the upper RPM ranges and frankly the fact that this pull stops at 6,800 is kind of a surprise as we can virtually guarantee you that the line on the graph was still rising at a rapid rate when the handle was pulled back. That being said, it is always easier to us to sit here and spin someone’s very expensive engine to RPM levels that they don’t want to tread on. We’d have been chomping or finger nails even as this big Ford lump was tickling 7,000!

So as neat as that 400hp 428 is in the front of a classic Mustang, we’d pick this 800hp 557ci monster every day and twice on Sunday. Of course you need to gut the front end of your car to have room for the damned thing to fit, but hey, we all make sacrifices to go fast, right?

PRESS PLAY TO SEE A 557CI JOB KAASE FOR HEMI MAKE 844 NATURALLY ASPIRATED HORSEPOWERON THE DYNO –