Rust Boat Engine

[JCGator]

Anyone know what engine this boat is running? Havent seen the boat in person but always see it on airboat madness stuff on social media. I'm just curious to know about the rig and cant find any other info. thanks.

3:59
https://www.youtube.com/watch?v=RAlubK8UBUg&ab_channel=AirboatMadness

 

[BobBrack]

That appears to be an angle valve IO-540. I bet it has been "doctored up" on the inside. I saw this boat run at the races a few weeks back. I cant say anything except Extremely Impressed!!!!!!!