My boat has a 4cyl, 3.0 Liter, 1988 GM block engine with an OMC cobra outdrive. I cuurently have a 13 3/4 x 15 prop and I am running at approx. 4300 rmp @ WOT at a speed of 32 mph. I am not sure of the engins HP. I was told probably 125hp. Is this right or should I go up in pitch. What do you think?<br /><br />Thank you,<br /><br />Eric