I have only been in 2 v-drive cruisers. one rode like a flaty and the other rode like a standard issue I/O. the rough ride was a old heavy ass Hallet. dont ge me wrong, it took the big water were I would have been a little nervous in a flat but it was a rough ride. The other boat was a light layup newer boat and I dont recall the make. It is Ducky's dad's boat. NICE RIDE. Your boat looks like it has a deeper V than the hallet and will ride good I think. does it have adjustable cav plates? If it does it will make all the differance in the world.
as for the tranny, It's a 1 speed w/ reverse, correct? If you are happy w/ the way it comes out of the hole and the RPM's you are turning I wouldn't worry about a TH400.
By the way. Dont worry about stearing when in reverse. both boats sucked at that. wink