I went down to try out a new motor bracket fitting to see if the shorter shaft 3.5 HP motor would work, as it's a heckuva lot easer than trying to wrestle the 6.5 HP into place on the transom. I made a mock up out of a well-aged piece of Georgia yellow pine and two pieces of douglas fir. The motor, seated on the modified bracket, did sit low enough to bury the exhaust port and, more importantly, the intake for the water pump. But it also blocked the gear shift so that I cannot get the motor into "Forward," which is sort of important, and it also blocked the pin that gets pushed in to keep the engine in the "Up" position and the prop out of the water.
So back to the drawing board.
Then I put a kayak in to take a quick paddle out to the point and also get a better look at the bracket. Maybe, just maybe, if I flip the bracket over 180 degrees, it'll lower the O/B enough to not need the new configuration.