Aquanoob,
I have the same boat with a 175 Etec. With a light boat, 1/4 tank of fuel, no gear, and just me on board I had her pushing 50 mph. I can say she didn't like it much. It was fine on a flat surface going straight, but she tends to chine walk in a turn. Its a bit unnerving. I usually run at 3500 - 4000 rpms and around 30 - 35 mph. She handles well at that speed.