I would ask like I mentioned is the computer a 3 connector or 2 connector - thats why I brought that up so many times because you never know what is really going on - when you do not have eyes / hands and ears on things in person and really still dont especially from the start of the first post.

If I recall correctly you can read engine hours from ecm to pcm when selecting wrong engine app when scanning. Again find out the computer connectors 2 or 3 and get a pic of the ecm / pcm plus its sticker and how about a snap shot of the engine serial number. At this point in time its a guess what and why the engine header is incorrect.

You can NOT use a ecm 555 in place of pcm 555 the engine sides - just saying

I just can not believe if someone was selling a boat or its ecm / pcm that they would not have all their ducks in a row and and chit together to show all the correct info. But thats the way it is today.