Lost only keys and need key code. Went to local Ford dealer but they said they couldn't get me the code because the truck was too old.

1989 ,you sure its a chipped key ,wouldnt have thought so ,but reading question again then thinking about it ,,,key code ,,,, different answer right take the door lock barrell out and take it to a auto locksmith and they can make one to fit ,get three made ,some makes have a number on the door lock barrell but please dont ask me to remember what ones ,,,at my age i have a job remembering what i had for breakfast

A locksmith may be able to help in this situation and supply a key