As the next part of my project, I am looking at repowering the boat. The transmissions are due for a rebuild and the one engine seems to get water in the oil. I wanted to ask everyone's opinion.

Should I pull the current engines/transmissions at the end of the season and attempt to rebuild those? Should I look for a good deal on a couple of 318s and have them completely rebuilt and then installed after they are complete?

I would have the engines/transmissions pulled. Service the transmissions and then reinstall everything. Sounds simple but it won't be.