Give more info bro. From your 40 yard dash and height i can see you as a wide receiver/db. Whats your weight? If your Like 140 u could be a halfback. Give more info! Weight? Do you have good hands? Are you good at tackling?
You gave just enough information for me to tell you to try out for the track team. What I would need to know besides your weight, is can you catch? Can you tackle? Can you block? Do you have a high football IQ (can you learn plays and assignments)? Are you a leader? Once your coach figures out those questions, he will tell you where to play.