Rivals (1981)

After the death of his father, Adam moves (with his family) from their sheep farm in Wyoming to Los Angeles. Soon after arriving, Adam gets mixed up with Clyde, a mannerless bully who enjoys pulling pranks on Adam and putting him down for his rural image. Adam, in turn, gets back at Clyde on a number of occasions, and the two soon become rivals. When Clyde starts taking a fancy to Adam's sister, and his girfriend starts hanging out with Adam, relations between the two rapidly come to a head.