The M2B was a mid-engined rear-wheel drive monocoque design, monocoques having been popularised by Lotus's 25 of 1962.
Influenced by his aerospace experience, Herd built the chassis with Mallite, a material that had originally been designed for internal panelling in aircraft.
Mallite is a composite of balsa wood bonded between two sheets of aluminium alloy that is much stiffer than ordinary aluminium alloy, a useful characteristic for a racing car.
However, the material proved to be difficult to bend into the curved shapes needed and so, whilst the M2A prototype was made entirely of Mallite except for the steel bulkheads, on the M2B it was utilised only for the inner and upper skins, the remainder being aluminium alloy.
Mallite was also complicated to repair after crash damage.
Its use did mean though that the chassis was the stiffest then built for an open-cockpit car, with torsional rigidity of nearly 10,000 lb⋅ft (13,600 N⋅m) per degree.
Glass-reinforced plastic bodywork covered the nose, cockpit and engine.
Fuel was stored in rubber bag tanks situated within the moncoque.

Herd's knowledge of aerodynamics and Bruce McLaren's experience with Ford's sports car racing programme combined to spur the team into experimenting with aerodynamic bodywork.
The M2A was fitted with a rear wing that produced downforce – downwards pressure on the car and tyres which allows faster cornering – and reduced lap times by three seconds at a test at Zandvoort circuit in November 1965, two and a half years before the Brabham and Ferrari teams eventually debuted wings in a Grand Prix.
The team intended to use the wing on the M2B, but the engine problems that occurred prevented this.

The suspension was a conventional wishbone-based arrangement with inboard coilover springs and dampers at the front and outboard coilover springs and dampers at the rear.
Braking was provided by Girling discs within 13 inches (330 mm) diameter magnesium alloy wheels.
The wheelbase measured exactly 8 feet (2,400 mm), and front and rear track was 4 ft (1,200 mm) and 4 ft 10.75 in (1,492.2 mm), respectively.

For 1966 the Formula One engine capacity limit was increased to 3.0 litres from the 1.5 litres of the previous five seasons.
McLaren considered and discounted British Racing Motors (BRM), Maserati, Coventry Climax and Oldsmobile engines before opting for a Ford V8 engine.
This engine was originally designed for the Indianapolis 500, the premier single-seater oval track race in the United States, and had to be reduced in capacity from 4.2 litres to the 3.0 litre limit.
This choice was partly motivated by the belief that it might bring financial support from Ford, although this never materialised.
Ex BMW and Daimler-Benz engineer Klaus von Rucker was initially appointed to carry out the conversion of the engine in England.
However, progress was slow so the project was transferred to Traco Engineering in California, United States, where extensive modifications were made to the internals under the oversight of McLaren's Gary Knutson.
In its 4.2 litre form the Ford engine produced 470 bhp and McLaren expected the reduced capacity version to produce about 335 bhp.
In fact, it produced 300 bhp in a narrow power band and was further handicapped by its large size and weight; combined with the gearbox it weighed nearly as much as rival team Brabham's entire car.
In order to allow time to further develop the Ford, McLaren also used a Serenissima M166 3.0 litre V8 engine for some of the races.
This engine produced about 260 bhp and required modifications to be made to the monocoque but was at least relatively light and compact.
Four- and five-speed ZF transaxle gearboxes and a Borg & Beck clutch were employed.

The M2B was originally intended to be raced in a green and silver colour scheme designed by Michael Turner.
However, short on money, the McLaren team made a financial deal with the makers of the film Grand Prix – a drama that included actual race footage – which involved the car being painted white with a green stripe (edged in silver) in order to represent the film's
The M2B was a mid-engined rear-wheel drive monocoque design, monocoques having been popularised by Lotus's 25 of 1962. Influenced by his aerospace experience, Herd built the chassis with Mallite, a material that had originally been designed for internal panelling in aircraft. Mallite is a composite of balsa wood bonded between two sheets of aluminium alloy that is much stiffer than ordinary aluminium alloy, a useful characteristic for a racing car. However, the material proved to be difficult to bend into the curved shapes needed and so, whilst the M2A prototype was made entirely of Mallite except for the steel bulkheads, on the M2B it was utilised only for the inner and upper skins, the remainder being aluminium alloy. Mallite was also complicated to repair after crash damage. Its use did mean though that the chassis was the stiffest then built for an open-cockpit car, with torsional rigidity of nearly 10,000 lb⋅ft (13,600 N⋅m) per degree. Glass-reinforced plastic bodywork covered the nose, cockpit and engine. Fuel was stored in rubber bag tanks situated within the moncoque.
Herd's knowledge of aerodynamics and Bruce McLaren's experience with Ford's sports car racing programme combined to spur the team into experimenting with aerodynamic bodywork. The M2A was fitted with a rear wing that produced downforce – downwards pressure on the car and tyres which allows faster cornering – and reduced lap times by three seconds at a test at Zandvoort circuit in November 1965, two and a half years before the Brabham and Ferrari teams eventually debuted wings in a Grand Prix. The team intended to use the wing on the M2B, but the engine problems that occurred prevented this.
The suspension was a conventional wishbone-based arrangement with inboard coilover springs and dampers at the front and outboard coilover springs and dampers at the rear. Braking was provided by Girling discs within 13 inches (330 mm) diameter magnesium alloy wheels. The wheelbase measured exactly 8 feet (2,400 mm), and front and rear track was 4 ft (1,200 mm) and 4 ft 10.75 in (1,492.2 mm), respectively.
For 1966 the Formula One engine capacity limit was increased to 3.0 litres from the 1.5 litres of the previous five seasons. McLaren considered and discounted British Racing Motors (BRM), Maserati, Coventry Climax and Oldsmobile engines before opting for a Ford V8 engine. This engine was originally designed for the Indianapolis 500, the premier single-seater oval track race in the United States, and had to be reduced in capacity from 4.2 litres to the 3.0 litre limit. This choice was partly motivated by the belief that it might bring financial support from Ford, although this never materialised. Ex BMW and Daimler-Benz engineer Klaus von Rucker was initially appointed to carry out the conversion of the engine in England. However, progress was slow so the project was transferred to Traco Engineering in California, United States, where extensive modifications were made to the internals under the oversight of McLaren's Gary Knutson. In its 4.2 litre form the Ford engine produced 470 bhp and McLaren expected the reduced capacity version to produce about 335 bhp. In fact, it produced 300 bhp in a narrow power band and was further handicapped by its large size and weight; combined with the gearbox it weighed nearly as much as rival team Brabham's entire car. In order to allow time to further develop the Ford, McLaren also used a Serenissima M166 3.0 litre V8 engine for some of the races. This engine produced about 260 bhp and required modifications to be made to the monocoque but was at least relatively light and compact. Four- and five-speed ZF transaxle gearboxes and a Borg & Beck clutch were employed.
The M2B was originally intended to be raced in a green and silver colour scheme designed by Michael Turner. However, short on money, the McLaren team made a financial deal with the makers of the film Grand Prix – a drama that included actual race footage – which involved the car being painted white with a green stripe (edged in silver) in order to represent the film's
McLaren M2B