reduce column width for a template

I want to reduce my column width of a template so the right hand side widget will be on the right and not under the content.

I am able to reduce the width by decreasing the .span8 class but this does not focus specifically on the template but all templates on the site.

So by decreasing the blog preview width the widgets should then appear on the right on this page

http://goo.gl/99SVv4

thanks