In the book "Jack In The Box", Jack Twiller's experiences are followed from elementary to high school, while in his screenplay, William Kotzwinkle creates a younger brother, dividing these experiences between two separate characters.
The poster for East of Eden shows a picture of James Dean in his famous red jacket with the white t-shirt and jeans from _Rebel without a Cause (1955)_, a movie which came out on a later date.