Our prop shaft, 1 3/8" diameter, is about 6" too long for our new engine, so I have to cut it down.
I am thinking of having it hang out 3" further than in the photo from the support than present, to get the prop further from the 5" wide deadwood, and hopefully reduce vibrations.

How far out with the overhang can I go?
The blue support fin is very solid, and the shaft shows no wear after 2500 engine hours over 10 years use.
Thanks for advice form the experts