I always thought IIs were more "Economy?" version? (Minus the S88 J code.)
If you look at the VIN numbers. They indicate price class. Posted below you can see how the price class changes with the 2nd letter in the VIN. Don't quote these numbers I just used them to show you the difference.
Body Type: R = Plymouth Belvedere/Satellite
Price Class: H = High
Body Type: 23 = 2 Door Hardtop
Body Type: R = Road Runner
Price Class: M = Medium
Body Type: 23 = 2 Door Hardtop
Body Type: R = GTX
Price Class: S = Special
Body Type: 23 = 2 Door Hardtop
Body Type: R = Plymouth Belvedere/Satellite
Price Class: L = Low
Body Type: 21 = 2 Door Coupe
Here ya go.
1967 Codes:
First digit = car line
B - Plymouth Barracuda
C - Chrysler Newport / 300 / New Yorker
D - Dodge Polara / Monaco
L - Dodge Dart
P - Plymouth Fury
R - Plymouth Belvedere / Satellite
V - Plymouth Valiant
W - Dodge Coronet
X - Dodge Charger
Y - Imperial Crown / LeBaron
Second digit = Price class
E - Economy
L - Low
M - Medium
H - High
P - Premium
S - Special
K - Police
T - Taxi
O - Super Stock
Third and fourth digits = body style
21 - 2 door sedan
23 - 2 door hardtop
27 - Convertible
29 - 2 door sports hardtop
41 - 4 door sedan
43 - 4 door hardtop
45 - 6 passenger station wagon
46 - 9 passenger station wagon
Fifth digit = engine
A - 170 1-1BBL 6 Cylinder "G" engine
B - 225 1-1BBL 6 Cylinder "RG" engine
C - Special Order 6 Cylinder engine
D - 273 1-2BBL 8 Cylinder "LA" engine
E - 273 1-4BBL 8 Cylinder "LA" engine (High Performance)
F - 318 1-2BBL 8 Cylinder "LA" engine
G - 383 1-2BBL 8 Cylinder "B" engine
H - 383 1-4BBL 8 Cylinder "B" engine
J - 426 2-4BBL 8 Cylinder "RB" engine (Hemi)
K - 440 1-4BBL 8 Cylinder "RB" engine
L - 440 1-4BBL 8 Cylinder "RB" engine (High Performance)
M - Special Order 8 Cylinder engine
Sixth digit = model year
7 - 1967
Seventh Digit = Assembly Plant
1 - Lynch Road, Michigan
2 - Hamtramck, Michigan
3 - Jefferson, Michigan
4 - Belvedere, Illinois
5 - Los Angeles, California
6 - Newark, Delaware
7 - St. Louis, Missouri
8 - Export
9 - Windsor, Ontario, Canada