Yo,
More info inbound from
http://www.vintagebroncoparts.com/tech-corner.html
Some excerpts:
Dash Layouts & **** Location
Wiring Diagrams
1966 - 1977 Bronco Vehicle Identification
The VIN plate can be located on the inside face of the glove compartment door. Also, a second location were the VIN can be found is on the vehicle frame. It is stamped on the top, right hand frame rail and the approximate location is just slightly forward of the body mount bold that can be located on the passenger side foot well. Be advised the VIN is usually very lightly stamped and with the years of grime and corrosion buildup, you may have to use a wire brush and a mirror to read the VIN. I have also seen a white tag inside the drivers door well on 1974 models that had VIN number info displayed.
The VIN consists of a 11 alpha-numerical sequence that can be broken down into 4 separate categories, Series Identification, Engine Codes, Assembly Plant and Production Sequence
We will use this example of Vehicle Identification Number U15SLAE0010
Series Identification (first 3)U15
U13 = U100 Roadster (1966 - 1968)
U14 = U100 Pickup
U15 = U100 Wagon
Engine Code (single letter) S
F = 170 ci 2.8L 6Cyl 1BC Carburetor 1966-72
S = 200 ci 3.3L 6Cyl 1BC Carburetor 1973-74
A = 240 ci 3.9L 6Cyl 1BC Carburetor 1968
N = 289 ci 4.7L V8 2BC Carburetor 1966-68
G = 302 ci 5.0L V8 2BC Carburetor 1968-77
Assembly Plant (single letter)L
C = Ontario
D = Dallas, TX
E = Mawah
H = Lorain, OH
K = Kansas City
L = Michigan Truck Plant
N = Norfolk
P = Minneapolis / St. Paul
R = San Jose, CA
S = Allen Park, MI
U = Louisville
V = Kentucky Truck Plant
Production Sequence (the remaining number/letter combo) AE0010
Ser# From 732,001 Ser# Up To 914,000 Model Year 1966
Ser# From A00,001 Ser# Up To B82,000 Model Year 1967
Ser# From C00,001 Ser# Up To D82,000 Model Year 1968
Ser# From D82,001 Ser# Up To G30,000 Model Year 1969
Ser# From G30,001 Ser# Up To J70,000 Model Year 1970
Ser# From J70,001 Ser# Up To M30,000 Model Year 1971
Ser# From M40,001 Ser# Up To Q00,000 Model Year 1972
Ser# From Q00,001 Ser# Up To S60,000 Model Year 1973
Ser# From S60,001 Ser# Up To V00,000 Model Year 1974
Ser# From V00,001 Ser# Up To X40,000 Model Year 1975
Ser# From A00,001 Ser# Up To C75,000 Model Year 1976
Ser# From 00,001 Ser# Up To C75,000 Model Year 1977