Are you dead set on having the 911 fan shroud ? Jake Raby at massive type IV makes a really cool type IV fan shroud that works better than stock . Its called the DTM (down the middle) shroud . Its been made for the type IV engine that has been fit into a type I . His store's website is
http://www.aircooledtechnology.com/store/home.php . Check out his whole catalog , as he has some really cool stuff . Steve .