Blood is Thicker by Paul Langan

Hakeem Randall can't take it anymore. First he learns that his father is sick and his parents can no longer afford their home. Then he must leave his friends at Bluford High and move to his uncle's house in faraway Detroit. Things go from bad to worse when Hakeem is forced to share a small bedroom with his moody and secretive cousin, Savon. Once childhood friends, the two quickly become enemies. Now they are ready to to go war with each other, and the outcome of the battle promises to change their lives forever.