Mike,
Just liberate yourself from the cavitation burns and dings. I did it 6 years ago and never looked back and am still running those same still pristine SS. You have the perfect numbers to just drop one size. I was at 3800-3850 WOT, depending on how flat the test run was fully loaded, bait tanks, full water and fuel and 1 guy aboard with me.
Went from A3 to C2 and turned 3950 fully loaded. I have since added more chain, drinks, iron, extra oil, crap, crap crap and now turn about 3875 WOT. You should pick up from 100 to 150 rpm, so the change to C2 should end your problems. Don't know about safety locks but I have worried for years about them being taken off, but has not happened. There must a product and some prop shop should be able to tell you. Just do it. Hell, new SS props don't seem so expensive now that it costs me $800 to fill the boat with diesel, LOL. Good fishing to ya, Mikey.