The upper or top spring is the one that come out when you remove the accumulator. I have never removed one that did not have the upper spring, usally blue. This is just a old v6 car that my daughter drives to and from school so a soft shift is what im looking for. I must admit that I have never removed a 1-2 accumulator from a na V6. Only SC,s and v8 birds. I guess the question of the day is should I install a new spring on the top and bottom??
How hard do you want the shift? I put the Blue spring on top and the Purple bottom one back in because it's my girlfriend's car and she didn't want super hard shifts.
When I j-mod my Mark VIII, I will put a stiffer top spring in (probably the Light Green spring or Brown spring) and leave the bottom one out.
1-2 Bottom Springs:
F7AZ-7F284-BA 1992 1994 Violet
F3LY-7F284-A 1995 1997 Purple
F4UZ-7F284-A 1998 2000 Pink
1L3Z-7F284-AA 2001 2005 Dark Blue
1L3Z-7F284-BA 2001 2005 Yellow
1-2 Upper Springs:
1992 1993 Top spring not installed in production (Hey, look at that! lol)
F7AZ-7F284-CA 1994 1994 Dark Blue
F7AZ-7F284-AA 1995 1997 White
F75Z-7F284-AA 1998 2000 Light Blue
1W7Z-7F284-AA 2001 2005 Light Green
F75Z-7F284-BA Brown Top spring used in econoline vans, explorers, mountaineers, and f-150 pickup trucks. Very stiff. Never factory installed in production cars.