Put one, years ago, in one of my pops' old 1 ton dump trucks (I think it was a 77 truck, dunno engines year, but 60's I'm pretty sure). Thing ran STRONG for all the years he had it! Supposedly a "Police Interceptor" version, whatever that may mean, it did have a good lope to it's idle and unknown what the mileage was on it when we did this. Dunno anything about them, never did, just a good deal when we needed an engine.
Only sold it to buy another 5-ton truck. Moved around a 5500, or better, lb truck, with a 2+k load on it just fine. Empty, would lite up the dual rear tires pretty easily. I would think it would be perfectly fine motivating any jet boat.
Ray