Saildrive modification

I want to replace the Diesel engine on a friends sailboat with a different make engine, but want to re-use the existing gearbox and outdrive unit. This means I need to know the dimensions of the flywheel housing to gearbox interface flange and the engine output shaft geometry.

I'd have thought this type of information might be available on the web, but I've not been able to find it.

Some basic questions;

1. Is the gearbox interface flange and shaft design standardized in any way? Have folks like Yanmar patterned their engine design to enable bolt-in replacement of, say, a similarly sized Volvo Penta?

2. Can anyone point me towards design drawings for the interface flange and engine output shaft?

Many thanks!