Thanks everyone for your contributions.
I went back and reviewed my survey from 5 years ago. This is the verbiage from the survey:
1200 RPM - 8 MPH, 2700 RPM - 14 MPH, WOT 3600 RPM - 24 MPH.
The survey was on an inland lake with no wind or current. I was mistaken at the max RPM of 3450. To date, I have not pushed the engines much beyond 2900 RPM and I was in a passing situation on a tidal river and was not paying attention to the speed (Was trying to pass a barge)
My question resolves around experimenting with changing the props that were on for the sea trail above (which were 24"x24") which are on now, to the "spare props" that I intend to mount that are 26"x24".
What changes can I expect with the 26"x24" props with respect to WOT, cruising speed, and fuel efficiency.
I realize this is an open question, but I do appreciate your thoughts and recommendations.