I recently replace both props. They came with cavitation holes in the hub. I didn't plug the holes and the boat gets up on plane adequatly. Will plugging the holes have any advantage once the boat is on plane and running ?

From what I've read the water flow over the holes at speed and the vacuum area behind the prop will prevent exhaust from escaping.
That's providing you are using the thru prop exhaust system and not thru the transom, otherwise the holes don't do anything.

See previous thread regarding vents:

http://www.offshoreonly.com/forum/sh...threadid=26913

Answers anyone???

The previous thread talks more about getting on plane. I'd like to know if there is any performance change once the boat is up on plane and running with or without the holes plugged. Is acceleration better or a higher RPM or higher speed ?

No, the holes do nothing once you're up on plane.
They are only there to allow exhaust gasses to escape allowing the prop to slip a little and so the engine to gain RPM and get into the power band so getting out of the hole isn't as difficult.

And like I said if you have thru hull exhaust and none of the exhaust goes through the prop then the ventilation holes do nothing for you.