Hitman's Pontiac Trans Am Site
The Second Generation Trans Am Information Site

Engine, Transmission, and Rear End Codes

All the numbers, all in one place

Engine Codes

Now I also have quite a few people ask me for clarification on Engine Numbers for their specific year. I have put down the main engine codes here, but there are more, I just put down the most popular. I have most of the years here from 1967 to 1981. I have listed the Pontiac 400's, Olds 403, etc. for the Pontiac Trans Ams, Firebirds, and Formulas. When looking at the engine, at a quick glance, you can notice the difference between the Pontiac 400 and the Olds 403 because the Olds 403 has the oil filler tube located at the front of the engine.

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Pontiac 400 Olds 403

Where are all the codes......

On the Pontiac 400 or 455, you can look on the passenger side of the engine block, just below the heads for the engine code. And on the same side, real low on the block would be the VIN number. Now, the VIN number stamped on the engine will not be the full VIN number. It will be something like "28L111111". So, it will have a "2" for Pontiac, an "8" for the year built, an "L" for what plant it was built at, and then the "111111" would be the last 6 digits of the car's VIN number. If you look at the bottom of the engine, you will see a 400 or 455 casted into the block which can tell you at a quick glance if you have the Pontiac 400 or the Pontiac 455.

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For the Pontiac Engines, here is a good shot of an engine out of the car to see it better.

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On the Olds 403, on the drivers side of the block just below the heads located behind the power steering pump is the VIN number, and on the top of the engine behind the oil filler tube is the engine casting code.

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1967

Pontiac 400
Manual Automatic
WI - WQ
WU - WZ
YT - XN

 

 

 

 

 

1971

Pontiac 400
Manual Automatic
WK - WS
WT
XX - YS
YX

 

Pontiac 455
Manual Automatic
WC - WJ
WL
YC - YE

 

 

 

 

 

 

 

1975

Pontiac 400
Manual Automatic
WT YS

 

Pontiac 455
Manual Automatic
YZ

 

 

 

 

1979

Pontiac 400 (W72)
Manual Automatic
PWH

 

 

Olds 403
Manual Automatic

 

Q6 - QE
QJ - QK - QL

 

Pontiac 301
Manual Automatic

 

X4 - X6

1968

Pontiac 400
Manual Automatic
WZ YT

 

Pontiac 400 HO
Manual Automatic
WQ YW

 

Pontiac 400 Ram Air
Manual Automatic
WU - WI XN - XT

1972

Pontiac 400
Manual Automatic
WK YS - YX
ZS - ZX

 

Pontiac 455
Manual Automatic
WD - WM YB - YE

 

 

 

 

 

 

 

1976

Pontiac 400
Manual Automatic
WU - WT Y9 - YS
YZ - ZK

 

Pontiac 455
Manual Automatic
WX WX

 

 

 

 

1980

Pontiac 301
Manual Automatic

 

XC - XM
XN - YN

 

Pontiac 301 Turbo
Manual Automatic

 

YL

 

Chevy 305
Manual Automatic

 

CEL - CEM

1969

Pontiac 400
Manual Automatic
WZ YT

 

Pontiac 400 Ram Air III
Manual Automatic
WQ YW

 

Pontiac 400 Ram Air IV
Manual Automatic
WH XN

1973

Pontiac 400
Manual Automatic
WK - WP
WS - Y6
YG
Y3 - XN
YS - YX
YZ - ZK
ZX

 

Pontiac 455
Manual Automatic
WT - WW YA - YC
YD - YK

 

Pontiac 455SD
Manual Automatic
W8 Y8

 

 

1977

Pontiac 400 (L78)
Manual Automatic

 

XA

 

Pontiac 400 (W72)
Manual Automatic
WA Y6 - YG

 

Olds 403
Manual Automatic

 

VA - VB
U2 - U3

1981

Pontiac 301
Manual Automatic

 

BD - BJ

 

Pontiac 301 Turbo
Manual Automatic

 

BO - CJ

 

Chevy 305
Manual Automatic

 

D6A - D6B
D6D - DHA
DHB - DHC
DHD - DHF
DHH - DHJ
DHK - DHU
DHZDJ
DKB - DND

1970

Pontiac 400
Manual Automatic
WK - WS
WT
XX - YS
YX

 

Pontiac 455
Manual Automatic
WC - WJ
WL(HO)
YC
YE(HO)

 

 

1974

Pontiac 400
Manual Automatic
WT - Y3 AD - AH
AT - YT
YZ - YF
YH - ZJ
ZX - YL
YM - A3
YT - AT
ZS - ZT

 

Pontiac 455
Manual Automatic

 

AU - YW - YY

 

Pontiac 455SD
Manual Automatic
W8 Y8

1978

Pontiac 400 (L78)
Manual Automatic

 

YA - YU

 

Pontiac 400 (W72)
Manual Automatic
X7 WC

 

Olds403
Manual Automatic

 

VA - VB
U2 - U3

Transmission Codes

 

 

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Where are all the codes......

 

 

Rear Axle Codes

The axle code, which is a two-character code, is stamped on the front passenger side axle tube to the left of the carrier case. For example, axle code PX G70621 found on a 1977 Trans Am would be deciphered as; PX = Ring and Pinion Gear size 3.23(shown below), G = Manufacturer, Chevrolet Gear and Axle, 062 = Julian date which is the 62nd day of 1977 or March 1, 1977, 1= is the shift when built, in this case 1st shift.

 

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Where are all the codes......

The axle code is stamped on the front passenger side axle tube to the left of the carrier case. Now Pontiac was famous for not being consistent with the location and placement of these numbers. So you might need to do a little digging and searching to be able to find the code, but it will be there somewhere. Sometimes I have seen the codes not even together in the same spot. There might be 2 numbers here, 3 numbers there.....

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1967

UN - 2.56 Rear Gear (Posi)
UP - 2.78 Rear Gear (Posi)
UR - 2.93 Rear Gear (Posi)
US - 3.08 Rear Gear (Posi)
UT - 3.23 Rear Gear (Posi)
UV - 3.36 Rear Gear (Posi)
UW - 3.55 Rear Gear (Posi)
UX - 3.90 Rear Gear (Posi)
UY - 4.33 Rear Gear (Posi)
XB - 2.56 Rear Gear (Open)
XC - 2.78 Rear Gear (Open)
XD - 2.93 Rear Gear (Open)
XE - 3.08 Rear Gear (Open)
XF - 3.23 Rear Gear (Open)
XG - 3.36 Rear Gear (Open)
XH - 3.55 Rear Gear (Open)

1971

CA - 2.73 Rear Gear (Posi)
CB - 4.10 Rear Gear (Posi)
CG - 3.73 Rear Gear (Posi)
CJ - 3.42 Rear Gear (Posi)
GY - 3.08 Rear Gear (Posi)
CK - 3.42 Rear Gear (Open)
GX - 3.08 Rear Gear (Open)
GZ - 2.73 Rear Gear (Open)

 

1975

PT - 2.56 Rear Gear (Posi)
PU - 2.73 Rear Gear (Posi)
PW - 3.08 Rear Gear (Posi)
PA - 2.73 Rear Gear (Open)
PC - 3.08 Rear Gear (Open)
PG - 2.56 Rear Gear (Open)

 

 

1979

PS - 2.41 Rear Gear (Posi)
PV - 2.41 Rear Gear (Posi)
PT - 2.56 Rear Gear (Posi)
PU - 2.73 Rear Gear (Posi)
PR - 2.73 Rear Gear (Posi)
PW - 3.08 Rear Gear (Posi)
PQ - 3.08 Rear Gear (Posi)
PX - 3.23 Rear Gear (Posi)
PP - 3.23 Rear Gear (Posi)
PO - 3.42 Rear Gear (Posi)
PJ - 2.41 Rear Gear (Open)
PH - 2.56 Rear Gear (Open)
PA - 2.73 Rear Gear (Open)
PC - 3.08 Rear Gear (Open)
PD - 3.23 Rear Gear (Open)

1968

UN - 2.56 Rear Gear (Posi)
UP - 2.78 Rear Gear (Posi)
UR - 2.93 Rear Gear (Posi)
US - 3.08 Rear Gear (Posi)
UT - 3.23 Rear Gear (Posi)
UV - 3.36 Rear Gear (Posi)
UW - 3.55 Rear Gear (Posi)
UX - 3.90 Rear Gear (Posi)
UY - 4.33 Rear Gear (Posi)
XB - 2.56 Rear Gear (Open)
XC - 2.78 Rear Gear (Open)
XD - 2.93 Rear Gear (Open)
XE - 3.08 Rear Gear (Open)
XF - 3.23 Rear Gear (Open)
XG - 3.36 Rear Gear (Open)
XH - 3.55 Rear Gear (Open)

1972

CA - 2.73 Rear Gear (Posi)
CG - 3.73 Rear Gear (Posi)
CJ - 3.42 Rear Gear (Posi)
CM - 3.42 Rear Gear (Posi)
GY - 3.08 Rear Gear (Posi)
CK - 3.42 Rear Gear (Open)
CL - 3.42 Rear Gear (Open)
GX - 3.08 Rear Gear (Open)
GZ - 2.73 Rear Gear (Open)

1976

PS - 2.41 Rear Gear (Posi)
PU - 2.73 Rear Gear (Posi)
PW - 3.08 Rear Gear (Posi)
PX - 3.23 Rear Gear (Posi)
LD - 3.23 Rear Gear (Posi)
PA - 2.73 Rear Gear (Open)
PC - 3.08 Rear Gear (Open)
PJ - 2.41 Rear Gear (Open)
PD - 3.23 Rear Gear (Open)

1980

PS - 2.41 Rear Gear (Posi)
PV - 2.41 Rear Gear (Posi)
PT - 2.56 Rear Gear (Posi)
PU - 2.73 Rear Gear (Posi)
PO - 3.08 Rear Gear (Posi)
PW - 3.08 Rear Gear (Posi)
PQ - 3.08 Rear Gear (Posi)
PX - 3.23 Rear Gear (Posi)
PY - 3.42 Rear Gear (Posi)
PO - 3.42 Rear Gear (Posi)
PJ - 2.41 Rear Gear (Open)
PH - 2.56 Rear Gear (Open)
PA - 2.73 Rear Gear (Open)
PD - 3.23 Rear Gear (Open)
PB - 3.42 Rear Gear (Open)
PC - 3.08 Rear Gear (Open)

1969

ZB - 2.56 Rear Gear (Posi)
ZC - 2.78 Rear Gear (Posi)
ZD - 2.93 Rear Gear (Posi)
ZE - 3.08 Rear Gear (Posi)
ZF - 3.23 Rear Gear (Posi)
ZG - 3.36 Rear Gear (Posi)
ZH - 3.55 Rear Gear (Posi)
ZK - 3.90 Rear Gear (Posi)
ZM - 4.33 Rear Gear (Posi)
YB - 2.56 Rear Gear (Open)
YC - 2.78 Rear Gear (Open)
YD - 2.93 Rear Gear (Open)
YE - 3.08 Rear Gear (Open)
YF - 3.23 Rear Gear (Open)
YG - 3.36 Rear Gear (Open)
YH - 3.55 Rear Gear (Open)

1973

CA - 2.73 Rear Gear (Posi)
CM - 3.42 Rear Gear (Posi)
GY - 3.08 Rear Gear (Posi)
CL - 3.42 Rear Gear (Open)
GX - 3.08 Rear Gear (Open)
GZ - 2.73 Rear Gear (Open)

 

 

1977

PS - 2.41 Rear Gear (Posi)
PT - 2.56 Rear Gear (Posi)
PW - 3.08 Rear Gear (Posi)
PX - 3.23 Rear Gear (Posi)
PJ - 2.41 Rear Gear (Open)
PC - 3.08 Rear Gear (Open)
PH - 2.56 Rear Gear (Open)
PD - 3.23 Rear Gear (Open)

 

1981

PS - 2.41 Rear Gear (Posi)
PV - 2.41 Rear Gear (Posi)
PT - 2.56 Rear Gear (Posi)
PU - 2.73 Rear Gear (Posi)
PQ - 3.08 Rear Gear (Posi)
PW - 3.08 Rear Gear (Posi)
PY - 3.42 Rear Gear (Posi)
PX - 3.23 Rear Gear (Posi)
PJ - 2.41 Rear Gear (Open)
PH - 2.56 Rear Gear (Open)
PA - 2.73 Rear Gear (Open)
PC - 3.08 Rear Gear (Open)
PD - 3.23 Rear Gear (Open)
PE - 3.42 Rear Gear (Open)

1970

COF - 3.08 Rear Gear (Posi)
COL - 3.36 Rear Gear (Posi)
COT - 3.07 Rear Gear (Posi)
COV - 3.31 Rear Gear (Posi)
COX - 3.55 Rear Gear (Posi)
COZ - 3.73 Rear Gear (Posi)
CRY - 2.73 Rear Gear (Posi)
COE - 3.08 Rear Gear (Open)
COK - 3.36 Rear Gear (Open)
COS - 3.07 Rear Gear (Open)
COU - 3.31 Rear Gear (Open)
COW - 3.55 Rear Gear (Open)
CRX - 2.73 Rear Gear (Open)

 

 

1974

CA - 2.73 Rear Gear (Posi)
CM - 3.42 Rear Gear (Posi)
GY - 3.08 Rear Gear (Posi)
CL - 3.42 Rear Gear (Open)
GX - 3.08 Rear Gear (Open)
GZ - 2.73 Rear Gear (Open)

 

 

1978

PS - 2.41 Rear Gear (Posi)
PT - 2.56 Rear Gear (Posi)
PW - 3.08 Rear Gear (Posi)
PX - 3.23 Rear Gear (Posi)
PP - 3.23 Rear Gear (Posi)
PJ - 2.41 Rear Gear (Open)
PH - 2.56 Rear Gear (Open)
PC - 3.08 Rear Gear (Open)
PD - 3.23 Rear Gear (Open)
PM - 3.23 Rear Gear (Open)