wow, w/the $$$$ you're speding I'd a gone w/diesels!
Far more economical and will def meet your TQ specs.
JMO

That would be a cool project, not many guys run diesels

I hear Ya,
I actually did consider it and priced it out but the costs were out of this world to convert. It was 70K to convert to a pair of Cummins B series. I know this may be hard to believe but after running all the prop, transmission and performance numbers my boat will actually cruise a bit faster with the gas strokers. Of course I'll be getting only about .65 gals per mile with gas as opposed to a better 1 mile per gallon with the Cummins. But with diesel costing more than gas plus the 70K it just doesn't make sense for me.

You just have to get different pistons to lower the CR. You can also make small CR changes with head gasket thickness and porting the combustion chambers.

I would get with Bob Mandera/rmbuilder on the best cam for what you want. I would think a cam with a 114 lob sep would have a flatter torque curve and maybe something with more like a .580 lift. That way it makes its peak power and torque lower in the rpm range where you need it.