Probabaly not very helpful at this point but Summit does list a PN for Hedman 351W swap headers, I don't know if they are any good though.
He is one of the forum regulars over at http://www.mustangii.net. He posts under the name NorthWestMustang.
alcino: A couple questions if you don't mind:
1. It said in the article you have a Canton Oil Pan. Which one do you have and did it need to be...