GMC 2003 C4C042 Owner's Manual page 346

Engine 7.2L
Power Steering GM Part
Fluid Filter No. 88892858
R
Secondary
CAT 1R0751
Fuel Filter
Pressure Caps -
RC 54
*Optional Davco (K28) D350921 spin
located on driver's side frame rail.
**Optional Cold Weather (KUK) Racor B6484GM
-
spin on type filter located on driver's side frame rail.
6-92
8.1L
GM Part
No. 88892858
GM Part
No. 25055052
GM Part
No. 15997145
-
on type filter *** Optional air filter (GM Part No. 88937525)
for C6/C7/C8 Models. Fits inside standard size filter
(GM Part No. 88937548) listed previously.
7.8L 6.6L
GM Part GM Part
No. 88892858 No. 88892858
GM Part
No. 15098649
GM Part GM Part
No. 15075118 No. 15075118