Similar to the words, falcon, or dome piece, head is a term used to refer to someone. It is a stand-in for other inferior words such as 'bro' or 'dude.' You can call someone a 'head' in direct conversation or refer to someone as a 'head.' Like, someone can say that there are mad heads at this ripper, or like, head, lets booze.
JM: Yo head, lets get grab that 30 rack and kill those in my room piece.
Jack: Nahhh, falcon, lets booze those on the bleachers.