The spark plug gap for a 1987 Ford LTD depends on the engine size. Ford used several different engines in the LTD that year.
You must check your owner's manual for the exact specification. The manual will list the correct gap for your specific engine (e.g., 4.9L V8, 5.0L V8, etc.).
Failing that, consult a reputable repair manual specific to your 1987 Ford LTD and its engine. A Haynes or Chilton manual would be good sources. Do not rely on a generic answer found online as the gap can vary significantly between engines.
