You should post this in the v-drive section, lots of good peeps there. On the commercial fishing boat I engineer I like 5200, Sikaflex....neither one are fun to remove down the road though. I hear the name Seagoing Putty quite a bit but never tried it.
What do you use to seal the pillow blocks and cav rod housing and through hull water pickup
3m #4200 marine silicone works very well. It will have some adhesive properties like any silicone but seals very well when properly applied, remains flexable over time and is made for the marine environment. It's also available at h.d./lowes etc. (around my area anyway) if your in a pinch. Sea going epoxy is for more permanent type installations like you shaft log or setting a jet pump intake adapter permanently in the hull.