Legendary MGB

Octagon Newsletter January 1996

By Alan Fraser

In 1959, Sydney Enever began work on a successor to the successful MGA. Initially designated EX 205, this project was to become the MGB with a monocoque body boasting greater interior room despite 3 fewer inches in length. Mechanically the first MGB closely resembled the MGA with the faithful 'B' series BMC engine bored out to 1798 c.c. and a higher rear axle ratio. Over the next eighteen years, the MGB was to soldier on with numerous changes and facelifts that were introduced to try to keep the model somewhat competitive with its more advanced contemporaries. I have attempted to compile a chronological order to these changes so that the MGB owner of today might have some idea of what was actually aboard his car when it was built. Where body numbers are known, I have included them in brackets. The convertible (GHN) models were designated "Tourer" with roll-up windows rather than "Roadster" with side curtains, etc.

In the rationalisation of BMC numbers in 1960, the MGA 1600 numbers were prefixed by 'G' for make of car: (MG); 'H' for size of engine (1400-1999 c.c.); third letter for type of body: ('N' for open two-seater, 'D' for coupe); fourth letter if found for variation from standard: ('L' for left hand drive, etc.); first number, model (started with MGA Mark II showing '2'). Therefore the MGB was identified initially as model '3', (i.e. GHN3). This system carried on to series '5' when the U.S. VIN system was adopted on what was to be Mark IV (or Series 6). Now that the reader is totally confused, carry on as I attempt to create a simplified list of a less than simple history.

May 1962 - first production car completed.(GHN3-101) 18G engine.

July 1962 - last MGA produced (101,081 produced)

September. 20, 1962 - MGB officially introduced.

February 1963 - Laycock Overdrive optional, folding top standard, factory hard-top option (19259).

August 1963 - 1964 model year. Closed-circuit breathing, 18GA replaces 18G engine (19586).

September. 1964 - 1965 model year. 18GB five bearing engine, oil cooler standard in U.K., electric tachometer (48767).

March 1965 - fuel tank increased from 10 to 12 gallons and supported by bolts rather than straps (56743). Door handles changed to push-button type (57986).

September 1965 - 1966 model year. The elegant GT was unveiled (first production GHD3-71933). Reversing lamps standard (Tourer 100414, GT 1016928).

November 1966 - 1967 model year (GHN3-108039). Anti roll bar standard on tourer.

February 1967 - US wire wheeled cars get octagonal hub caps.

April 1967 - Salisbury rear axle standardised on the tourer (129287).

November 1967 - 1968 model year - Fourth series (Mark II), 18GF engine. All-synchro gearbox from the MGC, dual circuit brakes, emission control equipment (air pumps etc.), alternator and negative earth electrics, automatic transmission optional, 'Nader' dashboard, pre-engaged starter, energy absorbing steering column, overdrive switch combined with wiper wand, headlight control and horn also on a wand, electric windshield washer pump in lieu of manual, shoulder belts standard, centre console, smaller instruments, rocker switches, separate oil and temperature gauges, hazard warning flashers (Tourer 138401, GT 139471).

May 1968 - new brake pressure warning light (147858).

October 1968 - 1969 model year, 18GH engine, (GHN4-158371, GHD4-58231). Solid coloured leather seats, piping same colour as seats, three wipers on tourer, simple stick-on side reflectors, front wing changed (indicator lamps closer to grille opening), reclining seats with headrests.

October 1969 - 1970 model year: Fifth series (Mk.III) - recessed "black hole" grille, stud mounted BL badge motif on each front fender just ahead of the doors, rubber inserts in bumper over-riders, RO style (Rubery Owen) wheels introduced, vinyl seats introduced, smaller steering wheel with three drilled spokes, split rear bumper this year only, heater standard on both models, optional up to this date, N. American tail-lights unique with amber flashers on bottom (on top in UK), sidelights replace reflectors, dipping rear mirror(GHN5-187170, GHD5-187841).

Late 1969 - aluminium bonnet replaced by steel.

August 1970 - 1971 model year, type 18GK engine, HIF-4 carbs. Solid rear bumper, over-riders are no longer "handed", new Michelotti top standard, boot interior light, ventilation and heating improved, new interior light, automatic trunk and hood stays to replace those infuriating rods (GHN5-219001, GHD5‑219002).

May 1971 - 250,000th MGB built (U.S. Specifications GT).

August 1971 - 1972 model year, 18GV engine, new padded fascia with glove-box and face-level vents, centre armrest with storage and ashtray, logo on steering wheel now red (GHN5-258001, GHD5‑258004).

Late 1971 - engine sump reduced to 6.9 U.S. pints, drain plug re-located, inertia seatbelts now standard.

August 1972 - 1973 model year. 18V engine, anti-run-on valve, carbon canister, steering wheel with slotted spokes, leather-bound gear lever, armrests on inside of doors, door mirrors standard on both doors, wiper arms black, heated rear window in GT, revised grille with black mesh, grille badge silver letters with red background (GHN5-294251, GHD5-296001).

August 1973 - 1974 model year, 18V engine, changes to engine bay for commonality with V8, radial tyres standard, automatic gearbox withdrawn, seat belt warning buzzer and light, GT withdrawn from California market.

January 1974 - large rubber blocks on bumpers in place of over-riders (Sabrina Bumpers).

Sept. 1974 - Federal Rubber Bumpers introduced, chassis raised 1.5", single 12-volt battery, V8 type engine mounts, HIF carbs except California.

December 1974 - GT withdrawn from N. American market.

January 1975 - 1975 model year. 18V engine, Zenith-Stromberg carb., servo assist brakes standard for all dual-line cars, badge on front bumper, boot lid and steering wheel centre now gold and black for 50th anniversary (1975 only) GHN5-367902.

June 1975 - Overdrive standardised on all models.

August 1975 - 1976 model year. Catalytic converter standard, badge changed to silver and black.

June 1976 - 1977 model year. Electric radiator fan (two for North America and Japan), thicker front sway bar, standardised rear sway bar, gear lever overdrive switch, sealed cooling system, electric clock, re-modelled fascia, four-spoke steering wheel, new top with zip-out rear window, pedal position changed for better 'heel and toe' (GHN5-410001).


September 1977 - 1978 model year. Passenger side mirror convex, second carbon canister added, tonneau cover standard (GHN5-471001).

May 1978 - 1979 model year. Radio speakers mounted in both doors.

March 1979 - start of North American 'Limited Editions' - 6682 LE's built for North America (does this include the 250 numbered Canadian cars?).

June 1979 - 1980 model year. Sixth series (Mark IV) - Identification numbering changed to comply with U.S. VIN system. 80 mph speedometer, headlight rims notched for easier adjustment, front suspension cross member modified in anticipation of fitting 'O' series engine. (501001).

October 22, 1980 last two MGBs completed (523001, 523002 respectively).

Some of the changes were based on home models and not seen on export models for a few more months. Others were always on export models and only options on home models (such as the oil cooler).

I hope this list is of use to the many MGB owners in the club. For more detailed information on your own car, there are many good books on the MGB with more comprehensive points of originality. And just when you think you have figured the whole thing out, you may discover that your MGB is uniquely different in some detail. Welcome to the wonderful world of MG!

Legendary MGB

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