How many hours on the engines?, original intake manifolds? Fuel burn per mile? Do you have a 50% safety factor?
Continuous time on boat as base, two weeks seemed to become a limit, perhaps not if were we in 30s instead of 60ish.
I would take along the basic tune up parts, spare hose for water intake, or at least a roll of rescue tape, sea water pump repair parts (impellers), spare wire and connectors, oil, coolant, trans fluid. Enjoy the trip!
count me in too!