Styling Blog Summary Block into columns

I am trying to style summary blocks into columns, per this question: http://answers.squarespace.com/questions/14969/styling-the-blog-summary-block-layout-into-columns

I want my block to break into 3 columns, 2 rows with 6 posts showing. I have watched Nick's youtube video and pasted embeth55's code from the above mentioned post into the header section of code injection, and adjusted for 3 columns, but am still only getting 1 vertical list of posts. Can anyone help? The code is below. Thank you for looking!

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js"></script>

<script type="text/javascript">
  $(document).ready(function() {


   var $elems = $('.summary-block').filter(function(){
    return $(this).data('block-json').pageSize === 6

})

    $elems.each(function(){
        $('.summary-item-list .summary-item', this).wrap('<div class="col sqs-col-4 span-4”></div>');

        $('.col > .summary-item').wrap('<div class="newSummary"></div>');
})

});
</script>