Originally Posted by Insequent
A few years ago I inspected a GB 42 In Seattle with a single Cat 3208. The engine was mounted really high, and it looked kinda odd. I don't remember the transmission, but possibly it had a V drive and that was why it was mounted so high.
The original gear was probably a BW VD. That's a planetary reduction drive and most modern gears aren't planetary. They have two gearbox shafts. The input and output shafts. They are vertically one above the other so the input shaft (in the gearbox) is above the output shaft. So the engine crankshaft (and thus the engine) needs to be raised the distance between the two shafts .. usually two or three inches.
That's my guess. However if it actually had/has a V drive the orientation of all the components of a V drive generally necessates a high mounted engine. Even then acessability to the shaft seal is poor. A V drive boat will almost always have a far aft mounted engine.
Since the GB boats typically have a rather far fwd mounted engine and a hull designed for that mounting a far aft engine would probably not be a good choice. A very unballanced boat will result. Possibly drier though.