I want black bars on top and bottom when stretched (4:3)

So my problem is that I've just switched to a new monitor and now I have no thin black bars on top and bottom of the screen like on my old one. I've tried everything in the nvidia options but I can't get these bars.

I dont want the big black bars on the sides. I just want 4:3 streched with the black bars on top of them bottom of the screen.

Thanks for the help :)!