Auto Parts: Ford Ranchero heads, ford ranchero, ford motorsport

Question
i have two sets of heads for a 302, one has a D70E casting number, which is the original set, and the new set has an F3JE casting number. i need to know if the compression cylinder would be the same cc's? Also, can i use the F3JE heads on the original block??

Answer
    The D7OE is a fairly ordinary casting from the mid '70's, but that F3JE casting is not in any of the references I have.  The "J" would indicate that it came from an industrial application, not a car or truck, although that is not for certain.  At any rate, if you are going to use them for performance purposes, they would probably be close to the same.  That newer head bothers me though.  Is it possibly an aftermarket replacement head, from Ford Motorsport?  That would explain the peculiar casting number.  If you don't know and can't find out where those '90's heads came from, then I would stick with the older ones, you can find out almost anything you need to know about modifying them from one of the Mustang websites.  Sorry I couldn't be of more help.