So I'm not sure if this can be done.
my 12valve is getting tired and needing rebuild.
but I have a marine 12 valve and would like to know if I swap the automotive out for the marine engine.

has anyone ever done this before?
what can I expect.

 

Expect to only be able to use the longblock. So all your accessories, bolt-ons, injection system, etc will likely need to be swapped.