Originally Posted by Cookee
It will need some serious hull modification to get the water into the jet unit and move the engine forward to make room for the jet unit - are you sure you want to do this? It would be easier to buy a jet boat!
Engine would be in the right position but you would definitely have to modify the hull from ~engine back. Also, you would probably want a new engine or you'd have to significantly modify the Cummins for increased horsepower since jet drives aren't as efficient (to maintain current performance).
Ask Sunrider what performance numbers he got out of his:
Willard 730 Jet for sale in the USA
Note in the attached pic how the vee disappears in the back of this Willard 540 Jet. Slightly different hull shape. I don't know if Willard has two hull molds or they lay a piece in the bottom of the reg mold and then glass over it.