MGB Identification

The MGB was produced from 1962 to 1980, and although they all look very similar, numerous changes were made to each model, over the nearly 2 decades of production.

When purchasing parts for your MGB, MGB GT, or GT V8, it is important that you know as much information as possible about the production details of your car, and where possible, any modifications that may have been carried out over its life.

Most importantly you will need to locate the chassis number (models up to 1979) or VIN (vehicle Identification Number, 1980 models only), which will not only identify the model and year of your car, but also its origin. In the case of MGB's in Australia, this number will identify (amongst other things) if the car was Australian or UK built, or if the car was imported from the US and converted to RHD, which was common place in the 1980s and early 90's.

Also of importance, is the Engine, Gearbox, Overdrive and Axle numbers which may be required when ordering parts for these units.

Location and Meaning of Chassis Numbers

1800cc (Early MGB)
The chassis number is stamped on a plate secured to the right hand wing valance forward of the radiator

1800cc (Later MGB)
The chassis number is stamped on a plate secured to the right hand side of the slam panel

1800cc (late MGB - US Models)
The chassis number and date of production is stamped on a plate secured to the left hand 'B' Post

1800cc (Early MGB)
The body number is on a plate secured to the left hand front valance behind the radiator diaphragm

1800cc (MGB Australian Models)
The body number is stamped into the left side of the bulkhead, adjacent to the heater unit.

1800c MGB
The commission number is stamped on a plate secured to the slam panel

GT V8
The chassis number is stamped on a plate secured to the right hand inner guard adjacent to the filter

GT V8
The body and commission numbers are stamped on plates secured to the left hand side of the slam panel

Chassis Number Prefixes (AU Models)

MGB's were assembled at both in Zetland Plant and at the Pressed Metal Company in Enfield NSW. The easiest way to identify which plant a car was built at is the manner of which the ID plate was stamped. Zetland plates were pressed from the back giving a tidy raised text, where as the PMC plant hand punched the plates from the front, and are usually quite haphazard in appearance.

YGHN3	MKI - 1962→69
YGHN4	MKII Overdrive - August→November 1968
YGHN5 & YHN5*	MKII Overdrive - From January 1969
YGHN6 & YHN6*	MKII Non Overdrive - From January 1969
YGHN7 & YHN7*	MKII Automatic
YGHN9 & YHN9*	Facelift / Fish mouth Models - "MGB BL" - Manual
YGHN10 & YHN10*	Facelift / Fish mouth Models - "MGB BL" - Automatic

*The "G" was dropped from the Chassis Prefix after the Leyland takeover

Decoding Chassis Numbers (AU Models)

Prefix	Y	Denotes AU built Cars
Make:	G	MG
Engine Type:	H	BMC B-Series engine, 1798cc
Body Style:	N	2 Door - Roadster
Series:	3	MK I - 1962→67
	4	MK II - August→November 1968
	5	MK II Overdrive - From January 1969
	6	MK II Non Overdrive - From January 1969
	7	MK II Automatic Models
	9	Facelift / Fishmouth models "MGB BL"
	10	Facelift / Fishmouth Models "MGB BL" - Auto
Car Number:	####	Number with 3 or 4 Digits

Chassis Number Prefixes (UK & US Models)

GHN3	MGB Roadster - 1962-67
GHN4	MGB Roadster - 1967-69
GHN5	MGB Roadster - 1969-79
GHD3	MGB GT - 1965-67
GHD4	MGB GT - 1967-69
GHD5	MGB GT - 1969-79
GD2D1	MGB GT V8 - 1972-76

Decoding Chassis Numbers (UK & US MGB Models)

Make:	G	MG
Engine Series:	H	BMC B-Series Engine, 1798cc
Body Type:	N	2 Door - Roadster
	D	2 Door - GT
Series:	3	MK I - 1962→67
	4	MK II - 1968→69
	5	MK III - 1970→79
Market:	R	Right Hand Drive Models
	L	Left Hand Drive Models
	U	USA - Left Hand Drive Models
Car Number:	###	Number with 7+ Digits
Year Model:	none	1968→69
	A	1969→70
	B	1971
	C	1972
	D	1973
	E	1974
	F	1975
	G	1976
	H	1977
	J	1978
	L	1979

Decoding Chassis Numbers (MGB GT V8 Models)

Make:	G	MG
Engine Series:	D	3000cc + (in this case 3500cc V8)
Body Type:	2	2 Door
	D	GT
Series:	1	Right Hand Drive Models
	2	Early Left Hand Drive Models
Car Number:	###	Number with 3 or 4 Digits

Location and meaning of engine and other major component numbers

1800cc MGB
The engine number is stamped on a plate secured to the right hand side of the engine block

3500cc MGB GT V8
The engine number is stamped on the left hand side of the cylinder block behind the left hand side cylinder head

Rear Axle - Banjo & Tube
The rear axle number is stamped on the front of the axle tube on the left hand side adjacent to the spring seat

3 Synchro Gearbox
The gearbox number is stamped on the top of the gearbox casing adjacent to the dipstick

4 Synchro Gearbox
(Including V8)
The gearbox number is stamped on top of the gearbox casing

All Overdrive units
The overdrive number is stamped on a plate secured to the main casing

Decoding Engine Numbers (MGB: B-Series 1798cc) - 18G engines

MGB Engine numbers can be broken down into 3 groups of alpha numeric codes, each being separated by a hyphen or slash.

(e.g. 18GA/R/H1234)

Group 1 :	18	1798cc (1800) capacity
	G	MG - 3 Main Bearing - Oct 1962→Apr 64	All Markets
	GA	MG - 3 Main Bearing - Apr 1964→Oct 64	All Markets
	GB	MG - 5 Main Bearing - Oct 1964→67	All Markets
	GD	MG - 5 Main Bearing - Oct 1967→69	UK, Europe & AU
	GF	MG - 5 Main Bearing - Oct 1967→69	North American
	GG	MG - 5 Main Bearing - Oct 1969→71	UK, Europe & AU
	GH	MG - 5 Main Bearing - Oct 1969→70	Europe
	GJ	MG - 5 Main Bearing - Oct 1969→70	North American
	GK	MG - 5 Main Bearing - Oct 1970→71	North American
Group 2 :	U	Centre gear change
	R	Overdrive
	RC	Automatic
	RWC	Centre gear change with Overdrive
Group 3:	H	High Compression
	L	Low Compression
	L (2nd)	Left hand Drive
	###	Engine Number (Exclusive to each engine)

Decoding Engine Numbers (MGB: B-Series 1798cc) - 18V engines

The MGB 18V Engine numbers can be broken down into 3 groups of alpha numeric codes, but unlike their 18G predecessor, groups 1 & 2 are not commonly separated with a hyphen or slash (e.g. 18V582Y-H123)

Group 1 :	18	1798cc (1800) capacity
	V	Vertical (inline)
Group 2 :	581F	Bf+Pf+We*
(See table to the right for Code key)	581Y	Bf+Pf+We*
(See table to the right for Code key)	582F	Bf+Pf+We+R*
	582Y	Bf+Pf+We+R*
	583F	Bf+Pf+Rc*
	583Y	Bf+Pf+Rc*
	584Z	Re+Bf+Pf+We*
	585Z	Re+Bf+Pf+We+R*
	672Z	Re+Bf+Pf+We+R*
	673Z	Re+Bf+Pf+Ck+We+R*
	797AE	Re+Bf+Pf+Ck+Hl+We*
	798AE	Re+Bf+Pf+Ck+Hl+We+R*
	801AE	Re+Bf+Pf+Ck+Jl+We*
	802AE	Re+Bf+Pf+Ck+Jl+We+R*
	846F	Bf+Pf+Tl+We*
	847F	Bf+Pf+Tl+We+R*
	Z	Carburettor crankcase ventilation, evaporative loss control and twin carburettors.
	AE	Carburettor crankcase ventilation, air temperature control and evaporative loss control.
Group 3:	H	High Compression
	L	Low Compression
	L (2nd)	Left hand Drive
	###	Engine Number (Exclusive to each engine)

Key to 18V - Group 2 Codes

Suffix letter to Group 2 codes
F	UK and Australian Market
Y	European Market
Z	North American Market

Reference codes for Group 2
Bf	Lucas 16ACR or 17ACR alternator with negative earth
Ck	Anti-run on valve
Pf	Pre-engaged starter motor (when not normally fitted)
R	Laycock overdrive
Re	Exhaust emission control
We	Centre gear change
Hl	Meets 1975 US Federal regulations
Jl	Meets 1975 Californian regulations
Tl	Meets 1975 requirements

MGB & V8 Spares

Identifying your MGB