Print manager preserves the aspect ratio of the image, thus it
will go to this 366X514, not 400x514.
For example, the image initially is 400x600.
It has the ratio of 2:3
You are able to custom resize it to 800x1200 cause the ratio is
the same.
but if you want to resize it to 850x1200, it's not possible.
If you would like to resize it to 400x514, you can use other
alternative software such as
http://www.gimp.org/
or
http://www.getpaint.net/
These are freeware, so you do not have to pay anything to
download these software.