The MGB and MGC share a unitary construction monocoque bodyshell with no separate chassis. The body's main strength comes from built-in box section members, with two front side members running back to a cross member behind the gearbox, linked at the front by the bolted-on front suspension cross member. The double-section sills provide the primary longitudinal strength and link the front structure to the rear side members, which sweep over the rear axle and continue alongside the boot floor. The front wings are bolted on but still contribute to the structural rigidity of the assembly.
The GT body differs principally in the addition of a windscreen frame panel, roof panel with cant rails, rear reinforcement panel for the tailgate, and rear quarter panels which incorporate most of the C-posts.
MGC Structural Differences
The MGC bodyshell is based on the MGB structure but incorporates a revised engine bay, a modified floor pan, and a deep U-shaped welded-in crossmember that combines the engine and torsion bar front suspension mounting points. These modifications mean an MGB shell cannot simply be substituted for an MGC, as the front end structure is fundamentally different. With fewer than 9,000 MGCs built, a replacement shell can save an example that would otherwise be lost to terminal corrosion.
Production Development
The basic design of the bodyshell changed very little during production, but the changes that were made, particularly in 1974 when the rubber bumper models were introduced, were comprehensive. New body number series with new prefixes were introduced. The front and rear wings were revised to accommodate the polyurethane bumpers, the front suspension cross member was raised by approximately one inch, the twin six-volt batteries were replaced by a single twelve-volt battery in a new box on the right-hand side, and the tonneau floor and battery access panel were redesigned. The rear valance was widened, the rear wings made narrower so their joints moved further outboard, and these joints were no longer lead-loaded.
Heritage Bodyshells
In 1988, British Motor Heritage introduced the re-manufactured MGB Roadster bodyshell, followed by the GT shell, a pioneering effort in the classic car world. Thousands of these bodies have been manufactured. Heritage bodyshells are supplied complete with fitted front wings, valance, bonnet, doors, and tailgate, with panels pressed from double-sided zinc-coated steel for substructure panels and single-sided zinc-coated steel for skin panels. The assembled body is electrophoretically coated and primed to current motor manufacturing standards.
Shell Specifications
Heritage shells cover the full range of MGB production variants. The 3-synchro Roadster and GT shells for 1965 to 1967 push-button door handle cars are bespoke builds requiring a complete and undamaged gearbox tunnel from the customer, the only item Heritage do not manufacture new. The 4-synchro chrome bumper shells cover 1968 to 1974 RHD Roadster and GT. Four distinct rubber bumper shell specifications cover the production changes within the 1975 to 1980 period.
A rubber-to-chrome bumper conversion Roadster bodyshell is also available, featuring a rubber bumper substructure clothed in chrome bumper wings, removing the guesswork from fitting chrome bumpers to a rubber bumper car.
Fitting Advice
It is strongly advised that a dry-run fitting of major mechanical units and items known to be tricky to fit, such as the radiator grille, is carried out before top-coat painting. Once painted, the threads of all captive nuts and studs should be cleared of paint before fitting out commences. The shell arrives as a bare primed unit requiring all mechanical components, trim, and fittings to be transferred from the original car or sourced new.