Found this info on another forum when I was searching for some other spring codes. Hopefully this will help others.

a 2004 F SuperDuty:

Rear Springs — F-Series
B — 3C34-5560-L
C — 3C34-5A975-D
D — 3C34-5A975-G
E — 3C34-5A975-K
J — 3C34-5A975-J
M — 3C34-5A975-E
N — 3C34-5A975-F
P — 3C34-5A975-C
S — 3C34-5A975-C

2003 manual
Front Springs — F-Series
B — F81A-5310-EA
C — F81A-5310-EA
D — F81A-5310-EA
E — F81A-5310-EA
F — F81A-5310-FA
G — F81A-5310-GA
H — F81A-5310-HA
I — F81A-5310-RA
J — F81A-5310-JA
K — F81A-5310-KA
R — 2C34-5310-AAB, 3,600 lb.
S — 2C34-5310-AAB, 4,000 lb.
T — 2C34-5310-ABB, 4,400 lb.
U — 2C34-5310-ACB, 4,800 lb.
V — 2C34-5310-ADB, 5,200 lb.
W — 2C34-5310-AEA, 5,600 lb.
X — 2C34-5310-AFA, 6,000 lb.
Y — 2C34-5310-VA
Z — 2C34-5310-WA

Front Springs — F-Series

B — F81A-5310-EA
C — F81A-5310-EA
D — F81A-5310-EA
E — F81A-5310-EA
F — F81A-5310-FA
G — F81A-5310-GA
H — F81A-5310-HA
I — F81A-5310-RA
J — F81A-5310-JA
K — F81A-5310-KA
R — 2C34-5310-AAB, 3,600 lb.
S — 2C34-5310-AAB, 4,000 lb.
T — 2C34-5310-ABB, 4,400 lb.
U — 2C34-5310-ACB, 4,800 lb.
V — 2C34-5310-ADB, 5,200 lb.
W — 2C34-5310-AEA, 5,600 lb.
X — 2C34-5310-AFA, 6,000 lb.
Y — 2C34-5310-VA
Z — 2C34-5310-WA
Front Springs — Excursion

B — YC35-5310-ABC
C — YC35-5310-ACC
D — YC35-5310-ADA
G — YC35-5310-GA
H — YC35-5310-HA
S — YC35-5310-SA
Rear Springs — F-Series

B — 1C34-5560-CB also 3C3Z-5560-CB
C — 1C35-5560-DB
D — YC35-5560-EA
M — YC35-5A975-AA
N — YC35-5A975-BA
S- 3C3Z-5560-CA one you should get for EX spring swaps.
Rear Springs — Excursion

A — YC35-5560-A

Rear SD 30mm bar.. F81Z-5A772-AA