Not much difference minus emission devices
Marine applications always used hardened valve seat inserts for sustained WOT use, and sometimes they are four bolt mains, where the passenger car and truck versions did not always have hardened valve seat inserts. Some real advanced salt water blocks have a rust preventing coating in the water jackets from aftermarket re-builders on high end stuff. There will not be any vacuum operated emission devices run off a TVS either if it is in tact still.
Bruce