The rule of thumb is to go now lower than 75% of maximum hull hp.
My 2510 MV (14 deg. deadrise) is pushed by twin F-115s. That gives me 230 HP on a hull that can handle 325 HP, or about 71%. Because I have twins, I have more prop area, less prop slip, and seem to do OK. I can get 40 mph at a WOT rpm of 5800, I can cruise at 24 mph at an rpm of 4200, and get about 9.0 gph at cruise. Not too bad. Because of less prop area and more slippage, I doubt that same boat would run very well with a single 225....although there are many who do so.
There are many days when twin F-115s are more than enough and due to chop I have to slow down. However, there are many days when I wish I could cruise at 28 or 30 without over-straining the engines.
The F-150 wasn't out when I bought the boat in 2002. When I re-power someday, I'll drop a pair of 150s on her. That is 92% of max hull HP. Whether they are Yamis, Zukes, or E-Tecs, that is still to be determined.
Bottom line...don't underpower. Better to spend the money up front and get somewhere between 80%-90% of max hull HP.
Dave