hey Eric,

What do you plan to do with the motor? If its just street driving rebuild the best set. If you want to make some power go aftermarket. No stock cast windsor head is very good. You will spend as much on porting them as an aftermarket set will cost. Go to Air flow research site and go to the articles there is a great head article there and they include the E7's and everything else.There are a lot of great windsor heads out there.
Good luck