The fs70 is 18oz so the 160 would be 27oz more on the front it mite balance with the battery towards the tail but it would end up being a heavy plane lands fast as it is without the extra wieght.
the cowl is wide plenty of room for the fs70 side mounted you need a extra long glow driver to reach it.
Just looked at the specs of your magnum 160 it would be to much for this little plane and to heavy