What size of prop and shaft are currently on the boat? What kind of speed are you wanting with the repower? How much $$$ do you have for a new engine? Lots of options out there, if you can narrow things down a bit, you will probably get some informative responses.
The FPT NEF 570 6.7L really fits well in the same space as a 3208 CAT and has 500 Mhp commercial Tier 3. You would give up some weight as well. I have a repower like that going on in RI right now and we have done a lot of 3208 repowers in and around the midcoast area with the NEF. How many hours a year and will it be recreational or commercial use? You could also consider the C90 8.7L engine as an option too.shes got a Cat 3208, 2 1/2 " shaft, 26 x 23 1/2 4 blade prop, looking to cruise around 20 , budget is open , but i am only going to re- power it once so want to do it right the first time