If you are not going to rebuild the transom during this time I would use the same length as what your old motor was or what the transom is now. Measure from the notch down to the bottom of the V. That is a 27 year old transom and it is really time to rebuild it. If you do rebuild it go with a 30” transom height.
FellowShip
__________________________________________________ ________
Just for the Grins
