Gearbox will be the weak link on a high output diesel if not able to handle 1500+ lbs feet of torque at a low 3100rpm.

Remember prop speed is needed to get top speed, 1-1 or overdrive is the way to go providing you motor has the torque to turn them.

Not looking for top speed, 50 or so will do it, looking for economy and reliability, longevity... i need to take clients an hour ride from the island to cartagena daily.

I know youve heard of cartagena! Its where the secret service guys go to buy hookers with taxpayer money lol