The code to compile the product name as a link is contained in this line:
PHP Code:
$lc_text = '<h3 class="itemTitle"><a href="' . zen_href_link(zen_get_info_page($listing->fields['products_id']), 'cPath=' . (($_GET['manufacturers_id'] > 0 and $_GET['filter_id']) > 0 ?  zen_get_generated_category_path_rev($_GET['filter_id']) : ($_GET['cPath'] > 0 ? zen_get_generated_category_path_rev($_GET['cPath']) : zen_get_generated_category_path_rev($listing->fields['master_categories_id']))) . '&products_id=' . $listing->fields['products_id']) . '">' . $listing->fields['products_name'] . '</a></h3> 
which as you can see applies a vast number of other values to arrive at the correct results. There are many factors that need to be taken into account which will not have occurred to you unless you have worked through all the logic, not just your barebones output desire.