Report Books - Dashboard Chart

Hello,

I have an automated report book and would like to expand the functionality to include charts (in addition to the existing cubeviews).  I was able to add the chart, but I'm struggling with trying to control the formatting.  I would like to modify the header and have the chart fill the page (too much white space). See below.

Thanks!

Is there a way to format the chart output, in particular I would like to enlarge the chart image and have it stretched across the page?