Panhof,

Your motor is the same internally as the one I describe in my very first post on this thread. All the 460 Marine engines are about the same.

There are several things you could do to increase performance. As delivered the 460 Marine engine has low compression and increasing c/r ratio by way of swapping out heads and/or pistons helps a lot. Adding a camshaft to the increased compression helps also.

Unfortunately these mods require significant engine surgery for the average person; don't know your abilities but some external bolt-ons can help noticably, such as a bigger carbuetor like a 750 or 850 cfm (re-jetting mandatory!) and playing with your distributor's ignition timing (rejettting mandatory!).

Paul