Likewise looking for a replacement engine for a Westerbeke
44Afour (vintage 2000) for which Westerbeke
no longer makes an EPA approved drop-in.
has been suggested by mechanics who I had look at this one. Off hand I was told to look at $20k by knowledgeable friend for the convert/install. Beta looks like a better deal-look at their site-(Beta Marine US Ltd. Distributors for Kubota based marine
) for what it's worth (no $ discussion-anywhere) On the CF look a Beta vs Yanmar; I get the impression Beta is equal or less expensive. More importantly while people who have not had problems with their chosen brand prefer it, people who have had to work on their engine dislike Yanmar as being difficult while Beta people talk simplicity.
The Beta site lists many dealers in your area, Ft L closest.