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My 1976 Nova SS NovaResource
Axle Codes
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Scott's Nova Resource Site

Axle Dimensions    |    Identification    |    Casting Numbers    |    Assembly Codes    |    Standard Axle Ratio Table

1962   |   1963   |   1964   |   1965   |   1966   |   1967   |   1968   |   1969   |   1970   |   1971   |   1972   |   1973   |   1974   |   1975   |   1976   |   1977   |   1978   |   1979

Rear Axle Dimensions

Year A B C
62-6743 1/2"50 3/4"57 3/4"
68-7942 3/4"53 1/4"60 1/4"

A = Mounting plate (center to center)
B = Backing Plate to Backing Plate
C = Wheel mounting surface (drum to drum)

Rear Axle Identification


Carrier Casting Numbers

Axle Type Casting Number Series Gearing
10 bolt 8.2"ED32118 22.73:1 & down
10 bolt 8.2"EDB3011633.08:1 & up
10 bolt 8.5"410409N 22.56:1 & down
10 bolt 8.5"410408N 32.73:1 & up
12 bolt ED32088 22.73:1 & down
12 bolt 30140PM133.08:1 to 3.73:1
12 bolt EDB3017443.90:1 & up

Rear Axle Assembly Codes

The rear axle ratio may be determined by finding the two- or three-letter serial number prefix in the following table. The 1962-63 serial numbers are located on the front, right side of the differential carrier. The 1964 serial numbers are found on the bottom of the carrier. The 1965-79 numbers are usually found on the front of the passenger side axle tube.

The codes have been compiled from many sources to make this page as correct as possible. There is no guarantee that the codes are complete or accurate, therefore, I cannot accept any liability or responsibility for damages incurred from the use of this information. It is my intention to help you as much as possible in deciphering your Novas rear axle code.

For information about how to change the gears in your rear axle, check out "The Watson Guide to Happy Rear Ends" written by Craig Watson.

If you've changed your gears or added a different wheel and tires combination then your speedo is probably not correct. Check out my GM Speedometer Recalibration page.


1970 and earlier axle code example: QY 01 01 G E
Ratio Month Day Plant Posi Source
See Below:
01 = January
02 = February
03 = March
04 = April
05 = May
06 = June
07 = July
08 = August
09 = September
10 = October
11 = November
12 = December
01 = 1st
02 = 2nd
03 = 3rd
04 = 4th
05 = 5th
06 = 6th
07 = 7th
08 = 8th
09 = 9th
10 = 10th
etc...
B = Buick
C = Buffalo
D = Cadillac
G = Detroit Gear & Axle
K = GM of Canada
M = Pontiac/Canada
O = Oldsmobile
P = Pontiac
W = Warren, MI
- = No positraction
D = Dana Positraction Differential
E = Eaton Positraction Differential
G = Detroit G&A Positraction Carrier
O = Oldsmobile Positraction Carrier
W = Warren/Warner Motive

1971 and later rear axle code example: GW G 218 D E
Ratio Plant Day of Year Shift Posi Source
See Below:
B = Buick
C = Buffalo
D = Cadillac
G = Detroit Gear & Axle
K = GM of Canada
M = Pontiac/Canada
O = Oldsmobile
P = Pontiac
W = Warren, MI
001 = January 1st
002 = January 2nd
031 = January 31st
etc...
D = Day shift
N = Night shift
1 = Day shift
2 = Night shift
- = No positraction
D = Dana Positraction Differential
E = Eaton Positraction Differential
G = Detroit G&A Positraction Carrier
O = Oldsmobile Positraction Carrier
W = Warren/Warner Motive

Axle Ratio Code Table

1962

DA - 3.36 open
DB - 3.08 open
DC - 3.55 open (4cyl - 3 speed manual)
DD - 3.55 posi (4cyl)
DE - 3.36 posi
DF - 3.08 posi
DH - 3.08 posi (6 cyl)
DJ - 3.08 open (metallic brakes)
DK - 3.08 posi (metallic brakes)
DL - 3.36 open (metallic brakes)
DM - 3.36 posi (metallic brakes)
DN - 3.55 open (4cyl - metallic brakes)
DP - 3.55 posi (4cyl - metallic brakes)

1963

DA - 3.36 open
DB - 3.08 open
DC - 3.55 open (4cyl - 3 speed manual)
DD - 3.55 posi (4cyl)
DE - 3.36 posi
DF - 3.08 posi
DH - 3.08 posi (6 cyl)
DJ - 3.08 open (metallic brakes)
DK - 3.08 posi (metallic brakes)
DL - 3.36 open (metallic brakes)
DM - 3.36 posi (metallic brakes)
DN - 3.55 open (4cyl - metallic brakes)
DP - 3.55 posi (4cyl - metallic brakes)

1964

DA - 3.36 open
DB - 3.08 open
DC - 3.55 open (4cyl - 3 speed manual)
DD - 3.55 posi (4cyl)
DE - 3.36 posi
DF - 3.08 posi
DH - 3.08 posi (6 cyl)
DJ - 3.08 open (metallic brakes)
DK - 3.08 posi (metallic brakes)
DL - 3.36 open (metallic brakes)
DM - 3.36 posi (metallic brakes)
DN - 3.55 open (4cyl - metallic brakes)
DP - 3.55 posi (4cyl - metallic brakes)

1965

BA - 3.08 open
BC - 3.36 open
BE - 3.08 posi
BF - 3.36 posi
BG - 3.55 posi
BJ - 3.08 open (metallic brakes)
BK - 3.08 posi (metallic brakes)
BL - 3.36 open (metallic brakes)
BM - 3.36 posi (metallic brakes)
BN - 3.55 open (metallic brakes)
BX - 2.73 open (327 - powerglide)
BY - 2.75 posi
BZ - 2.73 open (metallic brakes)
FD - 2.73 posi (metallic brakes)

1966

BA - 3.08 open 10-bolt
BC - 3.36 open 10-bolt
BE - 3.08 posi 10-bolt
BF - 3.36 posi 10-bolt
BG - 3.55 posi 10-bolt
BH - 3.55 open
BJ - 3.08 open 10-bolt (metallic brakes)
BK - 3.08 posi 10-bolt (metallic brakes)
BL - 3.36 open 10-bolt (metallic brakes)
BM - 3.36 posi 10-bolt (metallic brakes)
BN - 3.55 open 10-bolt (metallic brakes)
BO - 3.55 posi (metallic brakes)
BQ - 3.31 open 12-bolt (327 Special Hi-Per)
BR - 3.07 posi 12-bolt
BS - 3.31 posi 12-bolt
BT - 3.07 open 12-bolt (metallic brakes)
BU - 3.07 posi 12-bolt (metallic brakes)
BV - 3.31 open 12-bolt (metallic brakes)
BW - 3.31 posi 12-bolt (metallic brakes)
FI - 3.55 open 12-bolt (close ratio 4 speed)
FJ - 3.55 open 12-bolt (metallic brakes)
FK - 3.55 posi 12-bolt (metallic brakes)
FL - 3.55 posi 12-bolt
FM - 3.73 open
FN - 3.73 open (metallic brakes)
FO - 3.73 posi (metallic brakes)
FP - 3.73 posi
FQ - 3.07 open 12-bolt (327 Special Hi-Per)

1967

BA - 3.08 open 10-bolt
BC - 3.36 open 10-bolt
BE - 3.08 posi 10-bolt
BF - 3.36 posi 10-bolt
BG - 3.55 posi 10-bolt
BH - 3.55 open
BQ - 3.31 open 12-bolt (327 Special Hi-Per - A/C)
BR - 3.07 posi 12-bolt
BS - 3.31 posi 12-bolt
BT - 3.07 open 12-bolt (metallic brakes)
BU - 3.07 posi 12-bolt (metallic brakes)
BV - 3.31 open 12-bolt (metallic brakes)
BW - 3.31 posi 12-bolt (metallic brakes)
FI - 3.55 open 12-bolt (close ratio 4 speed)
FJ - 3.55 open 12-bolt (metallic brakes)
FK - 3.55 posi 12-bolt (metallic brakes)
FL - 3.55 posi 12-bolt
FM - 3.73 open
FN - 3.73 open (metallic brakes)
FO - 3.73 posi (metallic brakes)
FP - 3.73 posi
FQ - 3.07 open 12-bolt (327 Special Hi-Per)

1968

BA - 2.56 open 10-bolt
BB - 2.56 posi 10-bolt
BC - 3.36 open 10-bolt
BD - 3.36 posi 10-bolt
BI - 2.73 open
BK - 2.73 open
BL - 3.07 open 12-bolt
BM - 3.31 open 12-bolt
BN - 3.55 open
BP - 2.73 open
BQ - 2.73 posi 12-bolt
BR - 3.07 posi 12-bolt
BS - 3.31 posi 12-bolt
BT - 3.55 posi
BU - 3.73 posi 12-bolt
BV - 4.10 posi 12-bolt
BW - 4.56 posi 12-bolt
BX - 4.88 posi 12-bolt
PA - 3.08 open 10-bolt
PE - 3.08 posi 10-bolt
PH - 3.55 posi 10-bolt
PK - 3.55 open
PL - 3.55 open
PX - 2.73 posi 10-bolt
QE - 3.55 open
QL - 3.31 open 12-bolt

1969

BA - 2.56 open 10-bolt
BB - 2.56 posi 10-bolt
BC - 3.36 open 10-bolt
BD - 3.36 posi 10-bolt
BI - 2.73 open
BL - 3.07 open 12-bolt
BM - 3.31 open 12-bolt
BN - 3.55 open
BO - 3.73 open 12-bolt
BP - 2.73 open
BQ - 2.73 posi
BR - 3.07 posi 12-bolt
BS - 3.31 posi 12-bolt
BT - 3.55 posi
BU - 3.73 posi 12-bolt
BV - 4.10 posi 12-bolt
BW - 4.56 posi 12-bolt
BX - 4.88 posi 12-bolt
PA - 3.08 open 10-bolt
PB - 2.56 open 10-bolt
PC - 2.56 posi 10-bolt
PE - 3.08 posi 10-bolt
PX - 2.73 posi

1970

CBA - 2.56 open 10-bolt
CBB - 2.56 posi 10-bolt
CBC - 3.36 open 10-bolt
CBD - 3.36 posi 10-bolt
CBL - 3.07 open 12-bolt
CBM - 3.31 open 12-bolt
CBN - 3.55 open
CBP - 2.73 open 10-bolt
CBR - 3.07 posi 12-bolt
CBS - 3.31 posi 12-bolt
CBT - 3.55 posi
CBW - 4.10 posi 12-bolt
CPA - 3.08 open 10-bolt
CPE - 3.08 posi 10-bolt
CPI - 2.56 open 10-bolt
CPJ - 2.56 posi 10-bolt
CPO - 3.08 open 10-bolt
CPR - 3.08 posi 10-bolt
CPX - 2.73 posi 10-bolt

1971

BL - 3.07 open 12-bolt
BM - 3.31 open 12-bolt
BR - 3.07 posi 12-bolt
BS - 3.31 posi 12-bolt
PI - 2.56 open 10-bolt
PJ - 2.56 posi 10-bolt
PO - 3.08 open 10-bolt
PR - 3.08 posi 10-bolt
GJ - 2.56 open 10-bolt
GK - 2.56 posi 10-bolt
GR - 3.08 open 10-bolt
GS - 3.08 posi 10-bolt
GT - 3.36 open 10-bolt
GW - 3.36 posi 10-bolt

1972

GT - 3.36 open
JB - 2.73 open
JC - 3.08 open
JE - 3.42 open
JI - 3.08 open
JK - 3.42 open
JN - 2.73 posi
JQ - 3.08 posi
JS - 3.42 posi
JW - 3.08 posi
JY - 3.42 posi
PW - 2.73 open
PX - 2.73 posi

1973

JA - 2.73 open
JB - 3.08 open
JC - 3.42 open
JM - 2.73 posi
JN - 3.08 posi
JP - 3.42 posi

1974

JA - 2.73 open
JB - 3.08 open
JC - 3.42 open
JM - 2.73 posi
JN - 3.08 posi
JP - 3.42 posi

1975

GF - 3.42 open
JA - 2.56 open
JB - 2.73 open
JD - 3.08 open
JU - 2.56 open
JV - 2.73 open
JX - 3.08 open
JZ - 3.42 open
PA - 2.73 open
PC - 3.08 open
PH - 2.56 open
PT - 2.56 posi
PU - 2.73 posi
PW - 3.08 posi
PY - 3.42 posi
PZ - 3.42 open
2PA - 2.73 open
2PC - 3.08 open
2PU - 2.73 posi
2PW - 3.08 posi

1976

FK - 2.73 open
FG - 3.08 open
PA - 2.73 open
PC - 3.08 open
PH - 2.56 open
PT - 2.56 posi
PU - 2.73 posi
PW - 3.08 posi
PY - 3.42 posi
PZ - 3.42 open
2PA - 2.73 open
2PC - 3.08 open
2PU - 2.73 posi
2PW - 3.08 posi

1977

PA - 2.73 open
PC - 3.08 open
PH - 2.56 open
PT - 2.56 posi
PU - 2.73 posi
PW - 3.08 posi
PY - 3.42 posi
PZ - 3.42 open
TX - 3.08 open
TY - 2.73 open
TZ - 2.56 open
2PA - 2.73 open
2PC - 3.08 open
2PU - 2.73 posi
2PW - 3.08 posi

1978

PA - 2.73 open
PC - 3.08 open
PE - 3.42 open
PH - 2.56 open
PJ - 2.41 open
PS - 2.41 posi
PT - 2.56 posi
PU - 2.73 posi
PW - 3.08 posi
PY - 3.42 posi
2PA - 2.73 open
2PC - 3.08 open
2PU - 2.73 posi
2PW - 3.08 posi
2TV - 2.41 open
2TX - 3.08 open
2TY - 2.73 open

1979

PA - 2.73 open
PC - 3.08 open
PE - 3.42 open
PH - 2.56 open
PJ - 2.41 open
PS - 2.41 posi
PT - 2.56 posi
PU - 2.73 posi
PW - 3.08 posi
PY - 3.42 posi
2PA - 2.73 open
2PC - 3.08 open
2PU - 2.73 posi
2PW - 3.08 posi
2TA - 2.56 open
2TB - 2.73 open
2TC - 3.08 open
2TE - 2.41 open
Standard Axle Ratio Table

Below is a list of the standard gear ratios installed in Novas if a specific ratio was not ordered optionally. Performance and Economy ratios were available for most Novas but this list is probably going to cover the majority of Novas built. Novas with A/C got the same ratio as those without A/C unless otherwise noted.

1962
Engine Transmission Sdn/Cpe
Ratio
Wagon
Ratio
Ring Gear
Size
153 L4 3-speed 3.083.558.2"
Powerglide3.083.558.2"
194 L6 3-speed 3.083.368.2"
Powerglide3.083.368.2"

1963
Engine Transmission Sdn/Cpe
Ratio
Wagon
Ratio
Ring Gear
Size
153 L4 3-speed 3.083.558.2"
Powerglide3.083.558.2"
194 L6 3-speed 3.083.368.2"
Powerglide3.083.368.2"

1964
Engine Transmission Sdn/Cpe
Ratio
Wagon
Ratio
Ring Gear
Size
153 L43-speed 3.083.558.2"
Powerglide3.083.558.2"
194 L63-speed 3.083.368.2"
Powerglide3.083.368.2"
230 L63-speed 3.083.368.2"
Powerglide3.083.368.2"
283 V83-speed 3.083.088.2"
Powerglide3.083.088.2"

1965
Engine Transmission Sdn/Cpe
Ratio
Wagon
Ratio
A/C
Ratio
Ring Gear
Size
153 L4 3-speed 3.08n/a n/a 8.2"
Powerglide3.08n/a n/a 8.2"
194 L6 3-speed 3.083.363.368.2"
Powerglide3.083.363.368.2"
230 L6 3-speed 3.083.363.368.2"
Powerglide3.083.363.368.2"
283 V8
L32
3-speed 3.083.083.368.2"
4-speed 3.083.083.368.2"
Powerglide3.083.083.368.2"
283 V8
L77
3-speed 3.363.363.368.2"
4-speed 3.363.363.368.2"
Powerglide3.363.363.368.2"
327 V8 3-speed 3.073.073.368.875"
4-speed 3.073.073.368.875"
Powerglide3.073.073.368.875"

1966
Engine Transmission Sdn/Cpe
Ratio
Wagon
Ratio
A/C
Ratio
Ring Gear
Size
153 L4 3-speed 3.08n/a n/a 8.2"
Powerglide3.08n/a n/a 8.2"
194 L6 3-speed 3.083.363.368.2"
Powerglide3.083.363.368.2"
230 L6 3-speed 3.083.363.368.2"
Powerglide3.083.363.368.2"
283 V8 3-speed 3.083.083.368.2"
4-speed 3.083.083.368.2"
Powerglide3.083.083.368.2"
327 V8
L30
3-speed 3.083.083.368.2"
4-speed 3.083.083.368.2"
Powerglide3.083.083.368.2"
327 V8
L79
3-speed 3.073.073.318.875"
4-speed 3.313.313.318.875"

1967
Engine Transmission Sdn/Cpe
Ratio
Wagon
Ratio
A/C
Ratio
Ring Gear
Size
153 L43-speed 3.08n/a n/a 8.2"
Powerglide3.08n/a n/a 8.2"
194 L63-speed 3.083.363.368.2"
Powerglide3.083.083.368.2"
250 L63-speed 3.083.363.368.2"
Powerglide3.083.083.368.2"
283 V83-speed 3.083.083.368.2"
4-speed 3.083.083.368.2"
Powerglide3.083.083.368.2"
327 V83-speed 3.083.083.368.2"
4-speed 3.083.083.368.2"
Powerglide3.083.083.368.2"

1968
Engine Transmission Standard
Ratio
A/C
Ratio
Ring Gear
Size
153 L4 3-speed 3.08n/a 8.2"
Powerglide3.08n/a 8.2"
230 L6 3-speed 3.083.088.2"
Powerglide2.733.088.2"
250 L6 3-speed 3.083.088.2"
Powerglide2.733.088.2"
307 V8 3-speed 3.083.088.2"
4-speed 3.083.088.2"
Powerglide2.733.088.2"
327 V8 3-speed 3.083.088.2"
4-speed 3.073.078.875"
Powerglide2.733.088.2"
350 V8
L48
3-speed 3.313.318.875"
4-speed 3.313.318.875"
Powerglide3.073.078.875"
396 V8
L34
3-speed 3.31n/a 8.875"
4-speed 3.31n/a 8.875"
TH400 3.07n/a 8.875"
396 V8
L78
3-speed 3.55n/a 8.875"
4-speed 3.55n/a 8.875"

1969
Engine Transmission Standard
Ratio
A/C
Ratio
Ring Gear
Size
153 L4 3-speed 3.08n/a 8.2"
Powerglide 3.08n/a 8.2"
Torque Drive3.08n/a 8.2"
230 L6 3-speed 3.083.088.2"
Powerglide 2.733.088.2"
Torque Drive2.733.088.2"
TH350 2.733.088.2"
250 L6 3-speed 3.083.088.2"
Powerglide 2.733.088.2"
Torque Drive2.733.088.2"
TH350 2.733.088.2"
307 V8 3-speed 3.083.088.2"
4-speed 3.083.088.2"
Powerglide 2.733.088.2"
TH350 2.733.088.2"
350 V8
L65
3-speed 3.313.318.875"
4-speed 3.313.318.875"
Powerglide 3.083.088.2"
TH350 3.083.088.2"
350 V8
L48
3-speed 3.313.318.875"
4-speed 3.313.318.875"
Powerglide 3.083.088.2"
TH350 3.083.088.2"
396 V8
L34
3-speed 3.31n/a 8.875"
4-speed 3.31n/a 8.875"
TH400 3.07n/a 8.875"
396 V8
L78
3-speed 3.55n/a 8.875"
4-speed 3.55n/a 8.875"
TH400 3.07n/a 8.875"

1970
Engine Transmission Standard
Ratio
A/C
Ratio
Ring Gear
Size
153 L4 3-speed 3.08n/a 8.2"
Torque Drive3.08n/a 8.2"
230 L6 3-speed 3.08n/a 8.2"
Powerglide 2.73n/a 8.2"
Torque Drive2.73n/a 8.2"
TH350 2.56n/a 8.2"
250 L6 3-speed 3.08n/a 8.2"
Powerglide 2.73n/a 8.2"
Torque Drive2.73n/a 8.2"
TH350 2.56n/a 8.2"
307 V8 3-speed 3.083.088.2"
Powerglide 2.732.738.2"
TH350 2.562.568.2"
350 V8
L65
3-speed 3.083.088.2"
4-speed 3.083.088.2"
Powerglide 2.562.568.2"
TH350 2.562.568.2"
350 V8
L48
4-speed 3.313.318.875"
Powerglide 3.083.088.2"
TH350 3.073.078.875"
396 V8
L34
3-speed 3.31n/a 8.875"
4-speed 3.31n/a 8.875"
396 V8
L78
4-speed 3.55n/a 8.875"
TH400 3.55n/a 8.875"

1971
Engine Transmission Standard
Ratio
A/C
Ratio
Ring Gear
Size
250 L6 3-speed 3.08n/a 8.2"
Powerglide 3.08n/a 8.2"
Torque Drive3.08n/a 8.2"
307 V8 3-speed 3.083.088.2"
Powerglide 2.732.738.2"
TH350 2.562.568.2"
350 V8
L65
3-speed 3.083.088.2"
TH350 2.562.568.2"
350 V8
L48
4-speed 3.313.318.875"
TH350 3.073.078.875"

1972
Engine Transmission Standard
Ratio
Ring Gear
Size
250 L6 3-speed 3.088.50"
Powerglide3.088.50"
307 V8 3-speed 3.088.50"
Powerglide3.088.50"
TH350 2.738.50"
350 V8
L65
3-speed 3.088.50"
TH350 2.738.50"
350 V8
L48
4-speed 3.428.50"
TH350 3.088.50"

1973
Engine Transmission Standard
Ratio
Ring Gear
Size
250 L6 3-speed 3.088.50"
Powerglide 3.088.50"
307 V8 3-speed 3.088.50"
TH350 2.738.50"
350 V8
L65
3-speed 3.088.50"
TH350 2.738.50"
350 V8
L48
4-speed 3.428.50"
TH350 3.088.50"

1974
Engine Transmission Standard
Ratio
Ring Gear
Size
250 L6 3-speed3.088.50"
TH350 3.088.50"
350 V8
L65
3-speed3.088.50"
TH350 2.738.50"
350 V8
LM1
3-speed3.088.50"
TH350 2.738.50"
350 V8
L48
4-speed3.428.50"
TH350 3.088.50"

1975
Engine Transmission Standard
Ratio
Ring Gear
Size
250 L6 3-speed3.088.50"
TH350 2.738.50"
262 V8 3-speed2.738.50"
TH350 2.738.50"
350 V8
L65
3-speed2.738.50"
TH350 2.738.50"
350 V8
LM1
4-speed3.088.50"
TH350 3.088.50"

1976
Engine Transmission Standard
Ratio
Ring Gear
Size
250 L63-speed2.737.50"
TH200 2.737.50"
305 V83-speed2.737.50"
TH200 2.737.50"
350 V84-speed3.088.50"
TH350 2.738.50"

1977
Engine Transmission Standard
Ratio
Ring Gear
Size
250 L63-speed2.737.50"
TH350 2.737.50"
305 V83-speed2.738.50"
TH200 2.568.50"
350 V84-speed3.088.50"
TH350 2.568.50"

1978
Engine Transmission Standard
Ratio
Ring Gear
Size
250 L63-speed2.737.50"
TH350 2.737.50"
305 V84-speed3.088.50"
TH350 2.418.50"
350 V8TH350 2.418.50"

1979
Engine Transmission Standard
Ratio
Ring Gear
Size
250 L63-speed2.567.50"
TH350 2.567.50"
305 V84-speed3.088.50"
TH350 2.418.50"
350 V8TH350 2.418.50"


Main Page Copyright 1998-2003 Scott Windle Created on: 07/02/98 Updated on: 03/01/03