My '95 325 has twin Crusader 350XLi engines, which are fuel injected. I am not sure what the XL is, but the "i" is most certainly fuel injection.
I typically run at around 20~22mph at 3300~3400 RPM, which is fine for my sized boat, which is around 15,100 lbs as well. I think Bruce Toran and I have decided the hulls on our boats are identical, but with his boat having a cockpit, while mine has an aft-cabin. Why my boat weighs 100 lbs less is probably due to his boat having a 20 gallon higher gasoline capacity.
My boat also has VC-17 bottom paint, maintained with a new coat annually, which probably helps lower the drag. VC-17 is a freshwater paint only; but if you are on the Great Lakes, you might consider switching to it - as the boat picked up 1mph when doing so.
While 1 mph isn't a biggie, it is a 5% improvement, and it does show that the drag is lower.