Well, I guess, at least, someone has done it and, yes, the tranny problem is of significance. Although, Why not use the vehicle tranny? Certainly a tranny cooler could be added. And, a coolant exchanger could be used from many other applications. Leaving the manifold. Why not a welded one? And additional belt driven coolant pumps are very available.Say, you guys are talking me right into this. What a bunch of manipulators.

I've got the vee-drives in the boat. I'd think it would be lighter than the 318 Chryslers that are in there now. Less weight--less power needed. And I'd expect hull speed would need less than a hundred horses total. Anybody heard twin five-cylinder rigs power up with water lift mufflers?