I have a 1996 Marlin 20ft open bow with a Volvo Penta 5.0FL (basically a ford 302, from what I'm being told). The motor is ceized. I have tried using the marvel mystery oil to free it up and does not seem to be working. I came across a sweet deal on a Mercruiser 5.0XL and outdrive and want to know if I can swap them? What problems might i be facing?