Do a search on car-part.com. It will be under Engine Computer, (97 will be the newest update for a pcm programing) this will pull up a list for ECU (Electronic Control Unit) towards the bottom you will see the listings for the 7.3L. Find the tranny you have (AT or MT) then emmissions (Fed. "std" or Cali. "low") then the highest letter. Example = 1997 Fed. Auto trans. truck = F7TF-12A650-TB will be the newest PCM; F7TF-12A650-TA will the next newest, etc. Hope this helps.