Can someone "sticky" this to the top?
Here is a "mostly" complete list of RPO (Regular Production Options)codes Based on model year. You can find your "RPO" code list on the inside of your passenger glove box door.
2007 & up lists can be found here: Chevrolet Avalanche Zone 2007-

This list is for 2004 Avalanche
RPO DescriptionA31 Windows, power
A95 Seats, front Sport Cloth reclining buckets
A95 Seats, front Sport Leather seat inserts reclining buckets
AE7 Seats, front Custom Cloth 40/20/40 split-bench
AJ1 Glass, Solar-Ray deep tinted
AJ7 Air bags, side-impact, driver and right front passenger
AN3 Seats, front Leather seat inserts
AU0 Keyless entry, remote
AU3 Door locks, power programmable
B30 Floor covering, color-keyed carpeting
B30 Floor covering, color-keyed carpeting
B37 Floormats, Black, rubberized vinyl
BVE Assist steps, Dark Charcoal
BVR Assist steps, stainless steel, tubular
BVS Assist steps, Black (dealer installed)
BX2 Body hardware,
C49 Defogger, rear-window, electric
C5U GVWR, 6800 lbs. (3084 kg)
C5W GVWR, 7000 lbs. (3175 kg)
C6P GVWR, 8600 lbs. (3901 kg)
CF5 Sunroof, power
CJ2 Air conditioning, dual-zone, automatic
CJ3 Air conditioning, dual-zone, manual
D07 Console, floor
DF5 Mirror, inside rearview, electrochromic
DL3 Mirrors, outside rearview
DL8 Mirrors, outside rearview
DPF Mirrors, outside rearview, power adjustable, heated, camper-style,
E95 Cargo cover, rear, soft
EN4 Cargo cover, rear, rigid
FE9 Emissions, Federal requirements
G80 Differential, locking, heavy-duty, rear
GND Ground Effects Package
GT4 Rear axle, 3.73 ratio
GT5 Rear axle, 4.10 ratio
JF4 Pedals, power, adjustable
JL4 StabiliTrak
K05 Engine block heater
K34 Cruise control
K47 Air cleaner, high-capacity
K68 Alternator, 105 amps
KG3 Alternator, 145 amps
KNP Cooling, external transmission oil cooler
L18 Engine, Vortec 8100 V8 SFI
LM7 Engine, Vortec 5300 V8 SFI
M30 Transmission, 4-speed automatic
MN8 Transmission, 4-speed automatic, heavy-duty
N89 Wheels, 4 - 17" x 7" (43.2 cm x 17.8 cm) aluminum
NB8 Emissions override, California, Massachusetts, New York or Vermont
NC7 Emissions override, Federal
NE1 Emissions, Maine, Massachusetts, New York or Vermont state requirements
NP5 Steering wheel, leather-wrapped rim
NP8 Transfer case, electronic Autotrac
NZZ Skid Plate Package
PCY Wheel flare and Molding package, Black
PDA Sun and Sound Package, includes (U2K) Sound system feature
PDE Avalanche Texas Edition, includes (Z82) Trailering equipment
PDH Driver Convenience Package
PF9 Wheels, 4 - 16" x 7" (40.6 cm x 17.8 cm) aluminum
PY0 Wheels, 4 - 16" x 7" (40.6 cm x 17.8 cm) 8-lug forged aluminum
QAN Tires, P265/70R17, all-season touring, blackwall
QAS Tires, P265/70R17, all-season touring, white outlined-letter
QIW Tires, LT245/75R16E, on-/off-road, blackwall
QJM Tires, P265/70R17, on-/off-road, white outlined-letter
QJP Tires, P265/70R17, on-/off-road, blackwall
QMJ Tires, P265/70R16, all-season touring, blackwall
QMK Tires, P265/70R16, all-season touring, white outlined-letter
R6G Sun and Sound Package discount not desired
R6K Avalanche Texas Edition discount not desired
T96 Fog lamps, front
U2K Sound system feature, XM Satellite Radio
U42 Entertainment system, rear seat
UB0 Sound system, ETR AM/FM stereo with CD player
UC6 Sound system, ETR AM/FM stereo with 6-disc CD changer
UE1 OnStar
UJ6 Tire pressure monitor
UK3 Sound system feature, steering wheel mounted radio controls
UK6 Sound system feature, rear audio controls
UQ3 Sound system feature, 6-speakers
UQ7 Sound system feature, Bose Premium speaker system
V3A Grille, protector, brushed aluminum.
V54 Luggage rack, roof-mounted, Black
V76 Recovery hooks, 2 front, integrated into front bumper
VK3 License plate bracket, front
VYU Snow Plow Prep Package
WBH Without Body Hardware
YF5 Emissions, California state requirements
Z66 Suspension Package, Premium On-Road
Z71 Suspension Package, Off-Road
Z82 Trailering equipment, heavy-duty
Z85 Suspension Package, Heavy-Duty
ZQ1 Suspension Package, Smooth Ride
MSL - SILAO, MEXICO PLANT M30 - 4-SPD AUTOMATIC TRANSMISSION
B41 - CARGO AREA FLOOR MAT CF5 - ELECTRIC SLIDING SUNROOF
DT3 - REAR STOWAGE COMPARTMENT DT4 - ASHTRAY MUFFIN
YD3 - BASE EQUIP FOR SCH GVW PL-FT AX YD6 - BASE REAR SPRING
Front TR3 Up-Level Grille
AC6 - REAR PASS DOOR GLASS TINT CREDIT