Ran across this article a few years back, thought it would be good to post a link to it for reference. Should help with engine cooling, and reduce blockage in the rear water passages of the manifold:
http://www.broncofix.com/viewtopic.php?t=1...ht=351w+cooling
http://www.broncofix.com/viewtopic.php?t=1...ht=351w+cooling
