I have a set of 8 piston rings, four boxes with two sets per box. The part number is F8LZ-6148-AA which best I can figure translates to 1998 Lincoln Service Part - Piston Rings.
They have the thin 1.2mm top ring, so the set is 1.2mm/1.5mm/3.0mm and fits 1998-2002 Ford 4.6/5.4L DOHC 32v VIN V, X, or 9 including Lincoln, Continental, Mustang, and Triton truck engines.
As far as I can research, they cross to the following other manufacturers:
Grant C3931 & P3931
NPR SWF30008 & SWL03187
Sealed Power E914K
If anybody knows anything different, please let me know. I'm asking $50 + $6 for shipping USPS for this set which is a great deal since each box of 2 is over $100 at the Ford stealership.
One package opened up:
Crappy pic of me trying to show the difference between top 1.2mm and 2nd 3.0mm ring:
Another pic of top and 2nd rings:
Last pic of boxes: