Flexible Shaft Coupling R&D Marine

[Jma1_nemo]

Does anyone have an opinion on Flexible Shaft Couplings? In particular I'm looking at the R&D Marine flexible Shaft coupling. I searched the forum and found zilch.
Considering adding one to my CP-27 for a few reasons. The first is for what the advertisements proclaim, less vibration, easier alignment, less Torque on all components.  Another reason is the clearance between the front of my prop and the cutlass bearing housing is so close, I can't find a zinc thin enough to fit in there, so my logic is the Shaft coupling will gain me over an inch or so extra by pushing the Shaft further out thru the cutlass bearing. I have a pyi Max-Prop and I'm guessing it slides up the Shaft more than a regular prop which is why there is very little room between it and the cutlass bearing housing. The Max-Prop has a zinc on the very end, but I don't think that provides much, if any protection to the prop Shaft itself.  So I would appreciate any/all thoughts on this.  Thanks in Advance

[wes]

I have no experience with the flexible couplings, but I don't think you need to be too worried about the effectiveness of the existing zinc on your prop nut. As long as it is in good electrical contact with the shaft, which it likely is via the threads, it will protect the shaft from galvanic corrosion. I do think it's an especially good idea to inspect this type of zinc regularly since it's in a location that's vulnerable to damage.

Wes