The Counterman's definition of "work" was that they had the same threads and physical appearance for installation. Autolite 4164 plugs are resistor plugs. NGK D7EA is a non-resistor plug specified for your engine.
Experiences like these are why I have an intense distrust for parts counter men. They are paid to sell merchandise in stock, not for making your machine operate correctly.
It also seems that the more bravado, confidence, and assertiveness they exude, the less likely you'll get the right part.