Per Randy's spreadsheet, PS1 caps were sent to all 97-02 trucks, and PS2 caps were sent to all 03-04 trucks. The PS1 cap is wider but shorter than the PS2 cap.
The thing that really has me scratching my head is the fact that 24 kits received PS1 caps but only 7-8 people complained, and only 5 of those caps have been returned to me. The people who sent them back do not have a consistant year/make/model to make me think that Randy's spreadsheet was only off for a particular year.