I actually looked into building a boat like that with those motors when it was introduced a year or so ago. Those are actually marinized standard V10 Viper motors, not really anything to do with the comp coupe. They are putting out 550 because all the automotive smog stuff is not required. They cost in the same area as similarly equipped 540 cu. in. GM tall blocks. Unfortunately 550HP is not all that much in an offshore hot boat. It is about the entrance level right now with Merc 500's being the standard. For what those motors cost you could probably have 850 HP or so from a variety of well known relaible custom builders. The other downside is parts and service. Take it from someone who has built 2 custom offshore boats with exotic leading edge stuff on them....what you want is a wide variety and availbility of parts and service or that boat is gonna be on the traler for a month waiting to get fixed. And engines like those don't last longer than 200 hours without complete rebuilds. The problem is they spent too much of their time at wide open throttle. The same thing would happen to our cars if we ran them at 190MPH for hours on end. And I was very impressed when I saw that boat for the first time about a year ago, but not so impressed when I heard the 111 mph number. Just not that fast for a cat with exotic engines. You can get that kind of speed from a Fountain V bottom. A cat with big power is more in the 135+ range before we get to being impressive. Having said all that I love the idea of Viper powered boats, I just would not pay more to go slower and have more maintenance issues just to be able to say I had a Viper motor.