I would for sure replace the ujoint bellows. When they fail, the cost of boating goes way up, real fast.
It only takes about 1/2 to 1 hour to do the job, and well worth the effort.
Item #3 here http://forums.iboats.com/showthread.php?p=2360521#post2360521
The impeller would be another MUST do job before the first run.