bravo 2 or 3?
 

Ok, so this isn't for a go fast, but i figured this would still be a good place to get some info.

My dad just purchased a bayliner 2859 cabin cruiser with a single 7.4 merc and bravo 2. I had thought about upgrading to a bravo 3 since i hear it will be a more efficient setup with less prop slip, better time to plane, and better speed. Then somebody tells me that they aren't as strong and are no good for heavy boats.
My dads boat weights about 8k lbs. I understand the benefit of the bigger prop the bravo 2 allows, but would the bravo 3 be better and could it handle the boat? right now cruise speed is about 21-22 knots and 28-29 WOT and if i could get the cruise bumped up to 25 and wot over 30 it would make such a nice difference

The bravo 3 is actually rated for higher hp than the bravo 2. The bravo 2 is made for heavier boats & is made for a wider prop up to 20"s to help get a larger boat on plane easier. With this boat a bravo 3 will handle fine, but I have no idea what size props you will need.

That boat is maybe too big for a Bravo 3 - you cannot get props small enough in pitch to get the RPM out of the engine with the standard drive ratios. If you went all the way to a 2.43 ratio it might work.

The B3 should run much better but it will be expensive to find out for sure. Those big single engine/prop boats have a tendency to lean from the prop torque.