How many letters does the top answer for “director of long, long, long” have?

The most common answer is harrison (8 letters).

Crossword clue: director of long, long, long

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

harrison 8 letters wd-fact-v3

9th President of the United States; caught pneumonia during his inauguration and died shortly after (1773-1841)

director of 9-1-1 50% similar → bassett

director of 90210 50% similar → grimes

director of a very long engagement 50% similar → jeunet

director of her 50% similar → phoenix

director of q13415681 50% similar → hamill

director of q20856802 50% similar → gosling

director of q23685878 50% similar → levi

director of q60102 50% similar → adlon, shalhoub