I think I misunderstood your question. Mine is mounted at the back of the pulpit. It is over the rope locker but certainly not on top of the access hatch for the extra anchor/rope locker. I just replaced it with a new unit last weekend.
I have a 2000 265 with 200 HPDIs.
Best economy for me is 4000 rpm, 1.65 mpg, 32 mph with a medium load.
Top speed at 5600 is 44 mph.
I would be happy to answer any questions you have about the boat.