Some of them will be, but these two engines have had such a long and eclectic life that knowing which parts will fit which, even within their own respective models, is at best a crap shoot.
There are plenty of parts and service manuals
for both widely available on the web. A close perusal of these and comparison of relevant measurements given in the 'spec' sections of these manuals
might be a good place to start...
If the engine
was running before, and you drain and refill the oil
and run it up to full operating temp about three or four times, it will probably have no ill effects from it's dunking.
The engine still has value purely due to the number that are still out there.
The electrical system
will probably have to be replace, though if the boat was sunk in fresh water
, the starter and alternator
might be able to be 'dried out' and reused, though many will see this as a false economy.