You might find this install manual a little more informative than what comes with the BCR's.
http://forums.peddersusa.com/local_links.php?action=jump&catid=3&id=62
They do try to give a starting point for height adjustment.
http://forums.peddersusa.com/local_links.php?action=jump&catid=3&id=62
They do try to give a starting point for height adjustment.