headers for 350

i have a 2 sets of headers but i don't know what they go to. i could someone give me the mesurments for the ports. one of the sets of headers is shorter then the other. i can't find any numbers on them to tell me what they are. all i know is that they are new and are made by flow tech and the other set is used and is made by mr. gasket. i was woundering if they'd fit my 302 in my mustang?