I have an 82 #397 and the motor is a bit loud but I do not have any vibration issues. My guess is that although mounts wear out, if there is nothing causing the vibration they will still not vibrate too much. You need to isolate the cause of the vibration.
I would have the prop reconditioned, replace the cutless bearing, and have the shaft checked for being true and then have it aligned by a professional. I had this done last year and I could not belive how smooth the boat ran.
I would also check that your pullies for water pump, altenator etc are not out of round and that all the belts are tight. A loose belt can cause a lot of vibration.
It will never be really quite but it should be smooth with no large vibrations moving the winches around (-:
David
#397
