1978 Codes:
First Digit = Car Line
C – Chrysler Newport / New Yorker
F – Chrysler Le Baron
G – Dodge Diplomat
H – Plymouth Volare
M – Plymouth Horizon
N – Dodge Aspen
R – Plymouth Fury
S – Chrysler Cordoba
W – Dodge Monaco
X – Dodge Charger SE / Magnum XE
Z – Dodge Omni
Second Digit = Price Class
L – Low
M – Medium
H – High
P – Premium
S – Special
Third and Fourth digits = Body Style
22 – 2 Door special coupe
23 – 2 Door hardtop
29 – 2 Door special coupe
41 – 4 Door sedan
43 – 4 Door hardtop
44 – 4 Door hatchback
45 – 2 Seat wagon
46 – 3 Seat wagon
Fifth Digit = Engine
A – 1.7 Liter 1 – 2 BBL 4 cylinder engine
C – 225 1 – 1BBL 6 cylinder “RG” engine
D – 225 1 – 2BBL 6 cylinder “RG” engine
E – Special order 6 cylinder
G – 318 1 – 2BBL 8 cylinder “LA” engine
J – 360 1 – 4BBL 8 cylinder “LA” engine
K – 360 1 – 2BBL 8 cylinder “LA” engine
L – 360 1 – 4BBL 8 cylinder “LA” engine (high performance)
N – 400 1 – 4BBL 8 cylinder “B” engine
P – 400 1 – 4BBL 8 cylinder “B” engine (high performance)
R – 360 “Lean Burn” 8 cylinder “LA” engine
T – 440 1 – 4BBL 8 cylinder “RB” engine
U – 440 1 – 4BBL 8 cylinder “RB” engine (high performance)
Z – Special order 8 cylinder
Sixth digit = Model year
8 – 1978
Seventh Digit = Assembly plant
A – Lynch Road, MI
B – Hamtramck, MI
C – Jefferson, MI
D – Belvedere, IL
F – Newark, DE
G – St. Louis, MO
R – Windsor, Ontario, Canada
The remaining six digits indicate the sequence number (serial number)

1979 Codes:
First Digit = Car Line
E – Dodge Saint Regis
F – Chrysler Le Baron
G – Dodge Diplomat
H – Plymouth Volare
M – Plymouth Horizon
N – Dodge Aspen
S – Chrysler Cordoba
T – Chrysler Newport / New Yorker
X – Dodge Magnum XE
Z – Dodge Omni

Second Digit = Price Class
L – Low
M – Medium
H – High
P – Premium
S – Special
Third and Fourth digits = Body Style
22 – 2 Door B-pillar hardtop
24 – 2 Door hatchback
29 – 2 Door special coupe
41 – 4 Door sedan
42 – 4 Door B-pillar hardtop
44 – 4 Door hatchback
45 – 2 Seat wagon

Fifth Digit = Engine
A – 1.7 Liter 1 – 2 BBL 4 cylinder engine
C – 225 1 – 1BBL 6 cylinder “RG” engine
D – 225 1 – 2BBL 6 cylinder “RG” engine
E – Special order 6 cylinder
G – 318 1 – 2BBL 8 cylinder “LA” engine
H – 318 1 – 4BBL 8 cylinder “LA” engine
J – 360 1 – 4BBL 8 cylinder “LA” engine
K – 360 1 – 2BBL 8 cylinder “LA” engine
L – 360 1 – 4BBL 8 cylinder “LA” engine (high performance)
R – 360 “Lean Burn” 8 cylinder “LA” engine
Z – Special order 8 cylinder

Sixth digit = Model year
9 – 1979
Seventh Digit = Assembly plant
A – Lynch Road, MI
B – Hamtramck, MI
C – Jefferson, MI
D – Belvedere, IL
F – Newark, DE
G – St. Louis, MO
R – Windsor, Ontario, Canada
The remaining six digits indicate the sequence number (serial number)