How can I tell what year my "Air Judy Shox" were manufactured in?

need to replace the top air cap on my bike. I found an air cap for an '02 model (i think thats what mine is) but it has a schrader valve(mine uses a football needle to inflate). I would like to use the cap with the schrader valve. before i order it online i would like my verify what model year the shocks that i have are and that it will fit.