Re: 1995 volvo 3.0l engine upgrade
Get another boat that has the power you want, or find another complete engine and drive setup and install it.
The drive has to change as well as the engine. Different ratios for different sized engines. Before you ask, no just changing the prop won't cure the gear ratio problem. As soon as you change props to compensate for the bigger engine, you loose performance and go back to where you were with the 3.0L.
So you might just as well stay with the 3.0.