I tried using the key r on boot and the max resolution it lets me its 1024x768

Is there a way to force resolution?

You can edit the "burg.cfg" file [found in "/boot/burg/" and manually change it. Though, it should be noted that I did that with my 1680x1050 resolution and it appeared to be stretched [setting it to a square resolution fixed it, but not to my liking].