Something to immediately check for is overflow tubes in the carbbies.
Simple test: Grab one of your longer vacuum hoses and stick one end on the drain outlet of any of the carbbies. Do NOT unscrew the drain screw. Blow into the hose, if air flows, your engine is protected against hydrolock, if it does not flow, your engine is vulnerable to terminal damage. I would make this the #1 priority. Not all engines will suffer a hydrolock, but it is really ugly if you get one. Figure on replacing the engine.