Old deckhand
Guru
Does the boat have enough hull clerence to swing a larger diameter wheel?
From my files:
A client had a 37' Angel sport fisherman style boat powered by a pair of Iveco strait 6s. He found a "can't pass this up" deal on a pair of Cat 6s that would give him an extra 5 knots at cruise. Next he found a boat yard mechanic who could do the swap for a satisfactory fixed price.
Old story, but once into the swap the mechanic found that it wasn't as easy as he had figured, so he asked for more money, then when my guy wouldn't add to the pot, stopped work. My guy pulled the job, went to another mechanic, and came to me for the lawsuit.
The swap was done, including: new stringers so the wider stance of the Cats would fit and the whole works could be moved fwd, so the shaft angle would stay the same with the bigger shafts and taller props, new exhaust runs for the larger diam outlets, new floors above for the bigger, relocated access hatches, and so on.
What had been originally estimated at $40k went well over $100k, and recovery by way of the lawsuit was limited, as the original guy had next to nothing.