Customize above the fold

Hi,

Using Stream theme. Where do I customize the height of image section above fold on home page?
Not trying to adjust padding on header, but the section/container that takes up entire top of fold - that allows for an image with text over.

In Stream theme preview 'Featured Podcasts' would then appear above the fold.
In blog post layout, the default is about 2/3 of this home page size, which is closer to the size I'm looking for.

If you could let me know how to adjust. If this makes sense.

Thanks.