I have a 1985 Bayliner with volvo 3.0. it needs some motor work as to which I'm not sure of the extent yet. But was looking into worse case of needing a replacement. I found a 1984 Volvo 3.0. mine is omc Stern and that one is penta Stern. My outdrive has already been completely gone through so I'd assume keep it. But are motors interchangeable or would I have to swap a bunch of parts. Or at least are some parts compatible such as head, intake, exhaust? Sorry I'm not a boat mechanic so trying to find some help. Thank you.