Question regarding display size of BLOCK>Content Template

• I have pages that contain Query Loops.
• They connect to posts whose resulting displays are determined by Elements>Block-Content Templates I created.

The Post Information has a narrower (information window) width than the preceding page built with Query Loops (whose display of information is wider).
The Query Loop pages is approx 336 px wider. Visually - I like this wider display of information.

What I would like is for ALL pages to have this greater width, and the corresponding wider display of information.

Is there a way to set the "post" width when the only control I have over the page is the Content Template?

Any help is appreciated. Thank you!