Just to throw my 2 cents in the ring. I would go with the 330 Cummins, in fact I did. I would not put the 370 cummins in my boat, just pumped up too much, handgrenade with the pin pulled. As far as cost, 10k is a reasonable number to bed the engines, align, install the driplless stuufing boxes. I did all of the grunt work myself, and saved a lot of expensive labor. the end result. 25kt cruise at 17gph.

good luck.
JW

Also took me two months.