The 99-04 rails are all interchangeable AFIAK. The 98 was a one off return setup, the 96/97 were basic return rails and are considered an upgrade for the 98s. But that's just today's fun fact, does not apply to you lol.
2000 Mustang GT Steeda #0048 34k miles. 99 Cobra 4V swapped, FTBR IRS swapped, exhaust, tuned by James Gordon.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.