Cas,
If you start digging around through all the dyno sheets from most of the various pump gas N/A purpose built jetboat motors comming out of DNE, you'll see more of that similarity. In the quest to keep the power down in the useable RPMs, the torque curve will tend to peak and hold in the area of intended operation. Sure the motors make their peak number a little higher, and in some setups, the pump will alow them to get there. In my instance, we figgured I woudn't be spinning the impeller to more than 6k because of the size of my boat and associated impeller choices. You can see my tq curve is nice and flat, as is the power curve as well. If you were to look at other 498 build ups from different shops, you'd see some of them that might be able to get the hp a lot of us enjoy, but few have figgured out that it's much nicer to have access to that HP at lower RPMs, and how to do that as well as Dave.
http://www.***boat.com/forums/attach...achmentid=9698
Here is the sheet from my motor rigged as it went into the boat. The only difference between my motor now and during these pulls is the oil cooler, mechanical fuel pump, and a small change to the idle circuit.
Chris