Not sure they still used the Windsor in '84. My Ex had a 76 (or thereabouts) Cougar which used the 351M engine, which was a later varient of the 351C engine.They also made a 400M with the same casting. Sorta a small big block, or medium block if you will. They were strong torquey motors but finding aftermarket parts would be more of a chore. I seem to remember it was paint stamped on the valve cover.
It'll be interesting to see what you got!