You didn't say what kind of waterpump housing you were using, but this might be an interesting read. He had an over heating promblem with the top of the motor becoming hot.
Sorry, I can't get the address to post. Go to the engine section. It is locked as the third post down.
http://www.dodgecharger.com/forum/index.php/topic,60599.0.html

Last edited by 58pwrwgn; 03/18/10 08:53 PM.