Cleaned up version

<?php
//OUTPUT SECTION 1 POSTS
$args = array( 'post_type' => 'section-1', 'posts_per_page' => 3 );
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) :
    $loop->the_post();
?>
<div class="post_introbox">
    <div class="post_titlebox">
        <h3 id="post-<?php echo the_ID() ?>">
            <a href="<?php echo the_permalink() ?>">
                <?php echo the_title() ?>
            </a>
        </h3>
        <p>
            <span>
                <?php echo get_the_author_link() ?>
            </span> &middot; <?php echo the_date('m.d.Y') ?>
        </p>
    </div> //close titlebox
    <div class="containerz">
        <a href="<?php echo the_permalink() ?>"><?php
add_image_size( 'front-featured', 374, 250, array( 'center', 'center' ) ); // Hard crop left top

if ( has_post_thumbnail() ) {; // check if the post has a Post Thumbnail assigned to it.
    the_post_thumbnail( 'front-featured' );
}
?></a>
    </div>
    <div class="section_link_box">
        <span class="section1">
            <a href="/blog/<?php get_post_type( $post ) ?>">
<?php
$category = get_the_category( $custompost );
?>
                <?php echo $category[0]->cat_name ?>
            </a>
        </span>
    </div>//CLOSE SECTION_LINK_BOX
    <div class="spacer_one"></div>

    <div class="introtext section1">

        <?php echo the_excerpt() ?>
        <p class="more">
            <a href="<?php echo the_permalink() ?>">
                Continue Reading
            </a>
        </p>
        <div class="clearfloat"></div>
    </div>
</div>  //close introtext

<?php endwhile; ?>