Mr. Nicegye,
Cool looking boat.
The Mafia MF'er is right about labor and parts costs just to rebuild a stock
motor. Another option would be what we used to call a "Target engine".
These are either new or remanufactureed marine engines that are almost a
straight across swap. You would use parts from the old motor such as the intake
manifold and carb, distributor, starter ans alternator. If you have any
mechanical apptitude, you could possibly do the work yourself. Even if you had
to hier the engine swap done, you may come out ahead in the end.
Here is a link to a place that sells just such engines in assorted
horsepower.
Call them, and don't be afraid to ask lots of questions.
http://www.perfprotech.com/portal2/D...x=99&tabid=305

Good luck with it. Let us know how it comes out.
Gordo