You can Email any of the manufacturers for the more specific details of their filters. I use Hastings filters because I have a very good source.
The FF1160 is spec for 98. 502 and FF1260 is spec for 03-07.
When I emailed Hastings for the numbers, I got the following reply:
FF1160 has a 1 or a 2 nominal with a 10 absolute micron rating
FF1260 has a 1 or a 2 nominal with a 5 absolute micron rating
Both filters are exactly the same dimensions. I use the 5 micron filter in my '01. I see more pressure drop across it at WOT than I did with the 10 micron, but fuel pressure at the VP44 inlet still stays in the safe range.