Truck RPO Codes
TYPICAL GLOVE COMPARTMENT LABEL
(RPO CODES)

RPO is GM shorthand for Regular Production Option. These code describe the details of any Vehicle

This is aa aproximation of the RPO Code label that is found in all GM vehiles at the time of manufactiure.
 
Service Parts Identification 10108227 DO NOT REMOVE
1GNEC16K6RJXXXXXX 131.5 CC10906
 
 
AG9
AJ1
AS3
AT5
AU3
AU6
AXP
A31
A95
B33
B37
B85
B96
C5U
C60
C69
DK6
D48
D55
E55
GT4
JAN
JB6
K34
K68
LO5
MX0
M30
NA1
NB2
NK3
NRQ
N33
P06
QHA
R7M
SLM
TR9
UX1
U16
U88
VG8
VK3
VP6
VXS
V08
V22
V27
V73
XHA
X88
YA7
YD3
YD6
YE9
YF5
YHA
ZHA
ZQ2
ZQ3
ZY1
1SB
1SZ
13D
13I
50U
6WN
7WN
 
 
 
 
 
 
 
 
 
 


 
 
TRUCK ENGINE CODES
RPO ENGINE TYPE VIN 8
LB4 4.3L V6 TBI Z
L35 4.3L V6 CPI W
L03 5.0L V8 TBI H
L05 5.7L V8 TBI K
L19 7.4L V8 TBI N
LL2 2.8l V6 TBI R
LL4 6.2L V8 DIESEL J
LN8 2.5l L4 TBI E

 
EMISSIONS CODES
RPO
EMMISIONS
NA1
 UDER 8500 GVW
NA4
 OVER 8500 GVW
NA5
 FEDERAL
NB6
 CALIF, TIER 1
NB7
 CALIF, TLEV
NA6
 HIGH ALTITUDE
NF2
 FED, TIER 1
NM8
 LEADED FUEL COPMPATABLE
NN8
 UNLEADED FUEL, EXPORT
NB2
 CALIFORNIA
NRQ
 CC EXHAUST (T1)
FINAL DRIVE OPTION CODES
RPO
FINAL DRIVE
GU2
 2.73:1 
GU4
 3.08:1 
GU5
 3.23:1
GU6
 3.42:1 
G44
 3:.07:1
GT4
 3.73:1
GT5/GT8
 4.10:1
GM1
 2:59.1
HC4
 4.56:1

 
AUTOMATIC TRANSMISSIONS
RPO
HMD TYPE
DESCRIPTION
A3/M40 TH400/3L80 3 SPD (HD) NON - ELECTRONIC SHIFT ECM KICK DOWN CNTL

1st 2.48
2nd 1.48
3rd 1.00
R 2.08
A3 TH350/3L60 3 SPD (STD)

1st
2nd
3rd
R
MD8/A4 TH700R4/4L60 4 SPD NON - ELECTRONIC SHIFT ECM LOCK TORQUE CONVERTER

1st 3.06
2nd 1.63
3rd 1.00
4th 0.70
R 2.29
MD9 TH125R4 3 SPD NON - ELECTRONIC 

ECM LOCK TORQUE CONVERTER
M30 4L60E 4 SPD OD PCM CONTROLED SHIFT 
PCM LOCK TORQUE CONVERTER 

1st 3.06
2nd 1.63
3rd 1.00
4th 0.70
R 2.29
MT1 4L80E  4 SPD OD, (HD) PCM CONTROLED SHIFT
PCM LOCK TORQUE CONVERTER

1st 2.48
2nd 1.48
3rd 1.00
4th 0.75
R 2.08

 
MANUAL TRANSMISSIONS
RPO
TYPE
DESCRIPTION
M4
4 SPD
 MUNCIE 1st 
2nd
3rd
4th
R 
M28
6 SPD
 Borg-Warner, 85nn 1st 3.63 
2nd 
3rd 1.35
4th 
5th 
6th
R
MCO
4 SPD
 MUNCIE/GETRAG, (310 ft lbs) 1st 4.02 
2nd 2.30
3rd 1.40
4th 1.00 
R 3.74
ML9
6 SPD
 ZF, 90 mm, OD  1st 2.68 
2nd 
3rd 
4th 
5th 
6th
R 
268
5 SPD
 MUNCIE/GETRAG, w/OD, (310 ft lbs) 1st 4.02 
2nd 2.30
3rd 1.40
4th 1.00 
5th 0.73
R 3.74
MY2
5 SPD
 MANUAL, HMD w/OD 1st 4.02
2nd 
3rd 
4th 
5th 
R 
MY6
4 SPD
 MANUAL NEW PROCESS 1st 3.09
2nd 
3rd 
4th 
R 
MT8
5 SPD
 5 SPEED MANUAL W/Deep Low 1st 6.34
2nd 3.44
3rd 1.71
4th 1.00 
5th 0.73
R 6.34
MM5
5 SPD
 5 SPEED MANUAL W/OD 1st 4.02
2nd 3.23
3rd 1.40
4th 1.00
5th 0.73
R 3.74