Sounds like you are propped right. Full gear, livewells full, and full tank of gas should mean to most boaters poor hole shot. You are getting excellent speed. Look at other factors such as lift, is your boat getting out of the water at WOT. Might be able to add a little more cup to generate lift and holding power; Less boat in the water, higher speeds and RPMS. Engine Height could be something that would generate more speed. You are at the top of the RPM Band, and hole shot will get worse with a higher pitched set of blades. Sounds like you have reached the upper end of you speed capacity.
Good Luck