The Imp Site

Chassis Coding

Chassis numbering system, up to July 1970
Prefix letters
Suffix letters
Chassis Number Format, from July 1970 on
Product Code; Serial Number; Service Code
Trim Codes and Paint Codes

Earlier Chassis numbering system, up to July 1970

Prefix letters

All early Imps have a B prefix (as an 'A' denotes period 1950 - 1959 and prefix letter 'B' denotes model period 1960 - 1969). From '69 on, Imps lost their prefix.
(Prefix letters 'LB' indicate Linwood manufacture.)

Product Codes

The first three figures indicate the model. The next six digits are the Serial Number.
(If a car was exported in C.K.D. form (completely knocked down) then a 9 was put after the product code.)

Mark / Type 'Rootes' sometimes 'Chrysler'
(from '69 on)
announcedlast car (maybe)
(basic) Hillman Imp423
Hillman Imp Mk I421429
Hillman Imp de Luxe Mk I411419
Hillman Imp de Luxe Mk II412413
Hillman Imp Super442443
Hillman Californian401443402'69: 2329
Hillman Husky481482
Commer Imp Van462
Hillman Imp Van463463
Singer Chamois Mk I431 ?543 ?
Singer Chamois Mk II543 ?732 ? 733 '70 Apr. B733006587
Singer Chamois Sport 792793'69: 548
Singer Chamois Coupe 721722'69: 940
Sunbeam Imp Sport492493
Sunbeam Sport593L5 593 139499
Sunbeam Chamois733 ?543 ?
Sunbeam Chamois Coupe523
Sunbeam Stiletto3013024835
Sunbeam Californian401

Suffix letters

Three letters, indicating the following:
First letter
H - Home
R - R.H.D. Export
L - L.H.D. Export
E - C.K.D. Export Home Specification   (C.K.D.= completely knocked down)
W - C.K.D. R.H.D. Export
X - C.K.D. L.H.D. Export
Second letter
C - Convertible
H - Hardtop
L - Limousine
R - Roadster
S - Saloon
P - Pick-up
U - Estate Car
V - Van
X - Chassis only
Third letter
M - Ministry of Supply
O - Standard
X - Non-Standard
P - Police Specification

Example: a Dutch owned Sunbeam Chamois (1969 Feb) may have the following chassis number B 733 000683 LSO, in which LSO stands for L = left hand drive (export); S = Saloon; O = standard
However, a Stiletto that I know (1970 July) has no. LB 302 003034 LCO - Therefore C does not only stand for convertible but assumeably for coupé as well...

Richard McIntosh, Wed, 24 Jul 2013:
the best Imps of all are the B492-series Sunbeams ... especially after the front suspension had been amended. Very few of these are left. As the best ever Imp (in my opinion) there should be even more text dedicated to them ...


New Chassis Number Format

A new vehicle identification format was introduced in July 1970.

New chassis plate example:

Chassis
No.
G 302 631590
Service
Code
B SA XPaint
Code
108
Trim
Code
701Type
Code
211 H 4

Chassis No.

The Plant is indicated by the 1st letter:
L = Linwood
R = Ryton
The Series by the 2nd letter or digit
July 1970: G Series
July 1971: H Series
July 1972: 3 Series
July 1973: 4
July 1974: 5
July 1975: 6
The Product Code is indicated by the next 3 digits
(The same codes were used as previously.)
The Serial Number is the next six digits. These show the total production of all Imps derivatives since July 1970.
Commencing 000001 = Ryton
Commencing 600001 = Linwood
Commencing 900001 = C.K.D.

Example: my Stiletto, exported to Holland (1971 March): G 302 631590 BSA.
BSA refers to the Service Code.

Service Code

The Engine Code (1st letter):
A = Imp, 875cc Low Compression
B = Imp, 875cc High Compression
H = High compression [earlier]
The Transmission Code (2nd letter or number):
C = standard transmission [earlier]
S = Standard transmission, Imp [later]
The Option Code (3rd letter):
A = No other option
B = Servo brakes
C = Servo brakes and radio
D = Servo brakes and heavy duty suspension
E = Servo brakes, heavy duty suspension and radio
F = Radio
G = Radio and heavy duty suspension
H = Heavy duty suspension
The Market Area (4th letter):
H = Home, R.H.D. [later]
E = Export, R.H.D.
O = r.h.d. [earlier]
X = Export, L.H.D.
An Imp should have the same engine number as chassis number (if it is the original unit still fitted...). At least that's how it is with Stilettos, and I think that it is that way for all of Rootes' production.
The engine number might be stamped on a small flat area next to the distributor.

There's a Super Imp registered as PPR 276R on 1 December 1976 with chassis no. RICBA6L103422
Peter Fitzgerald has a 75 Super with Vin number R1CBA5L113581 and a service number which conforms to the L5 443 113581 BSAH format.

Most R registered Imps are Caledonians.


Much of the information given here was taken from Production figures & Chassis numbers / by Jack Salter. - Impressions 1987 August


UK Registration Plates - Year Identifiers

Suffix Letters

A

01 February 1963

31 December 1963

B

01 January 1964

31 December 1964

C

01 January 1965

31 December 1965

D

01 January 1966

31 December 1966

E

01 January 1967

31 July 1967

F

01 August 1967

31 July 1968

G

01 August 1968

31 July 1969

H

01 August 1969

31 July 1970

J

01 August 1970

31 July 1971

K

01 August 1971

31 July 1972

L

01 August 1972

31 July 1973

M

01 August 1973

31 July 1974

N

01 August 1974

31 July 1975

P

01 August 1975

31 July 1976

R

01 August 1976

31 July 1977

S

01 August 1977

31 July 1978

T

01 August 1978

31 July 1979

V

01 August 1979

31 July 1980

W

01 August 1980

31 July 1981

X

01 August 1981

31 July 1982

Y

01 August 1982

31 July 1983


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