With an NVidia card you should be able to do both 1360 and 1368. ATI can do at lease 1360. Set your panel to 1:1 pixel mapping and use 1368, it will clip one column from each side. If this doesn't work, use the driver control panel and the panel's width controls to adjust the width: in the case of 1368, there should be exactly 2 columns cropped from each side.
These pixelmatch images will allow you to see what's going on. DO NOT use Windows Picture & Fax Viewer, it crops the edges by 1 or more pixels in window and fullscreen mode. Use Irfanview
in fullscreen mode (be SURE to select in the Options menu, Properties, Fullscreen tab, then make sure first radiobutton is selected: "Show images/movies with the original size". You MUST set this option, because by default it will scale the image to screen size in fullscreen mode. Of course, that shouldn't matter because you MUST have your screen resolution set to the exact size of the image anyway.
The pixelmatch images are all black with resolution indicative text in the center. The outer edge has a 1-pixel red line, then inside that a 1-pixel black line, and inside that a 1-pixel green line. Showing 1368 on a 1366 monitor, the top & bottom should show both red and green lines. The right & left should show 1 black column, then a green column. Various sizes are available, to test different displays:1280x7201360x7681368x7681920x1080
You will never get 1366 via VGA (unless you use a Pixel Perfect
card, but you have to sacrifice some performance), because the RAMDACs on most cards only support mod8 horizontal resolutions. DVI can do this, but sadly most panels only support HDTV standard resolutions via DVI/HDMI (1280x720, 1920x540i, rarely 1920x1080p)