I bought a new AOC monitor that runs on native 1920x1080x75. I used to have a Samsung that ran on 1680x1050x60. Switching resolution was easy in game but vsynch stays at 60 fps? Can it be switched to 75? And how?

Wow, this forum is dead as a dodo.

Check the Skyrim.ini file for bLockFramerate=1 (change to 0). You may have to add it under the [Display] heading.

Also make sure you are running the new resolution at 75hz and not 60hz.