Jim is correct that the HP rating of the 25 is 200 HP. I know that most of the early "Cruise ships" originally came with 50 hp.
From what I saw when I was doing the repairs on the 2003 C Dory 25, I owned, I would not put twin 115's on it.
With the single 150 light boat, I get about 30 mph, With fully loaded for a months cruise, freezer, ref, full fuel and water, plus spare etc--I run easily at 18 mph and as the fuel is used can cruise in the low 20's.
I would think with 230 hp it is more than you want to run the boat at. I believe that some with the single Yamaha 200 are seeing in the 35 mph range with light boat and cruising in the high 20's. The boats don't really do all that well at speeds over 30..