my brother has a 1986 trophy 21ft fishing boat. the boat was very underpowered with a omc 3.0l motor which finally gave out at the end of last season. he is currently on his way to pick up a 4.3l omc motor which he plans to install with the original outdrive. i am not sure of the compatability of the 4.3l with the ratio that is stock with a 3.0l. any help would be appreciated, i am not familiar with omc and i dont want to see him get into any more trouble. i suggested he try and find a 4.3l omc outdrive. thanks, also does anyone know the correct gear ratios.....
