Nvidia sets 720p res 60 hz as default instead of 75hz

So lately I have been playing alot of CS:GO and lots of people are saying that more hertz is better, my monitor is a benQ GL2450HM 1080p 60hz. But I can however create a custom resolution in nvidia control panel to make it run in 720p 75hz. I would really prefer to play CS:go with this resolution but everything else in 1080p 60hz. However I have to go into nvidia control panel every time i want to change my resolution to 720p 75hz, If i just launch CS:GO while i'm using 1080p it goes to 720p 60hz. It won't go to 720p 75hz. I cannot figure out how to delete the 720p 60hz profile in nvidia nor can I figure out how to set 720p 75hz as a default setting when i change the video settings in a game to 720p. So does anyone know how I can delete a monitor preset or change defaults? My specs are:

Intel i5 2500, 
Asus 560 ti, 
8gb 1333Mhz Ram, 
500w Silver power 80+ PSU, 
60gb Corsair Force series 3 SSD, 
1tb Green WD drive, 
430 Cooler Master Elite, 



Why do you whant to play @720p? you can overclock your monitor to a faster Hz with the AMD catalyst not shure if these is a option in the nivida vershon have you had a look around the setings?

default analog crt monitors are usually upto 75hz and digital 60Hz (anless you buy a 120-144hz monitor)

My monitor can carry analog or digital and can run upto 75Hz if i use VGA (analog) and 60Hz (DVI/HDMI/DISPLAY PORT digital)

When I try to overclock my GL2450HM at 1080p it just shows a black screen, both DVI and VGA. 720p is the largest 16:9 resolution i managed to get 75hz to run on.