Sorry, but I'm confused. You wrote
In talking with the team, the boat was SBI Superboat Vee legal...
but according to your math
The average SVL runs around 12% prop slip. With a 30" pitch prop, (the average pitch raced), and a mandatory 1.5:1 gear ratio now, every 100 RPM is almost 2 MPH difference.
which would mean losing the 100s of rpm to really meet SBI SV tech would = enough mph to drop the kilo run to a sub-100mph performance, no?