Boyd appeared in other spectacles like "Billy Rose's Jumbo" (1962), "Genghis Khan" (1965), and "The Bible" (1966). He starred in the sci-fi adventure "Fantastic Voyage" (1966). His co-star in "Voyage", Raquel Welch, made sexual advances to him. He declined with, "An actress is a little bit more than a woman, but an actor is a little bit less than a man." She concluded from this remark (and later reported) that Boyd was gay. Boyd always had difficulty picking good scripts. His last movies were cheesy exploitation flicks made in Europe. He was married twice for very brief periods of time. He never came out as gay. He died of a heart attack while playing golf in California. 