Want to replace my rotovecta for ST40

I have an ST40 wind instrument with the rotovecta unit at the mast head and I am finding the unit not accurate enough for the trimming we are doing as we club race.
Can I replace the rotovecta with a vane and anemometer unit and will that make it as accurate as the ST60 I had on my previous boat?
If the answer to this question is no, and I need to replace both the head and transducer units, can I replace both and use the existing cables?
Dan