GM diesel

[jpduster]

MC must buy the whole car. Any one notice any Veedubs minus their motor out back of MC?

[maxpower220]

The VW engine isn't 30K more... The complete engine is like 18k, but you don't need an engine to start with.. So the whole upgrade would be like 9-10k.

First, the VW engine has to mate to a transmission. Most inboard boats have transmissions designed to bolt up to a 5.8 Ford or 5.7/6.0 Chevy. R&D and making a transmission to fit costs money. The fewer of them, the more expensive. Because of the torque that a diesel puts out, it may be that using exsisting transmission won't hold up and that precludes the use of an adapter plate.
Switching from gas to diesel also includes new ECU, pumps, tanks, etc. Just because it doesn't make sense, it is still a very expensive option.
Also don't forget, if you are the first to have a product and peope are willing to buy it, you can charge whatever you like.