Thanks for all of the suggestions. After reviewing all options, I chose to loosen the clamps and rotate the heat exchanger slightly back, CCW viewed from starboard zinc side. Only a few degrees allowed the zinc to clear the motor mount stud. Very easy fix. Access the clamp bolts from the back. See the subtle rotation in the photo.
There was no room on my boat to slide the exchanger slightly to port as it already hung up on the engine cover/stairs.
Zinc was completely gone when I bought the boat, and while I had a temporary solution in place, it is good to have this solid. From the look of my temporary, I may get 6-8 months life. /Ed