[6] At the same time, the oil dipstick was moved from the front of the engine to the side, the inlet manifold was improved from earlier models, and the compression ratio was raised slightly from 8.9:1 to 9.0:1 due to a change of the piston design.

[7] The shape of the inlet ports was also changed from an O-port design to a D-port design which improved the flow characteristics of the heads, the old 40 DFAV Weber carburetor that was prone to over-fueling and resulting bore wash was replaced by the 38 DGAS Weber carburetor, the air filter housing was also changed and later around 1976 a hot air intake was added consisting of a metal pipe running from the top of a plate welded on the exhaust manifold or header to an opening in the air intake to prevent the carburetor from icing and making the engine warm up more quickly.

[15] The GAA had the benefit of 100 mm (3.94 in) bores, DOHC aluminium alloy heads, Lucas mechanical fuel injection, a dry sump oiling system and a steel crankshaft and generated 462 bhp (345 kW; 468 PS) at 9,000 rpm and 300 lb⋅ft (407 N⋅m) of torque.

This engine was used in the racing version of the Capri RS 3100, competing successfully in the European Touring Car Championship, as well as in Formula 5000 single-seaters.

[19] Ford RS dealerships also offered a number of performance modifications for the Essex V6, called the "GP1" (Group 1) and "Series X", the GP1 package offered a 40 DFI5 Weber carburetor, a camshaft kit, larger, 44.5 mm (1.75 in), inlet and 41.3 mm (1.63 in) exhaust valves, double valve springs, specially selected connecting rods and forged high compression pistons giving a power output of around 170 bhp (127 kW; 172 PS).

Traces of its diesel design lie in the very heavy construction using Heron cylinder heads and the necessity for dished pistons to decrease compression for the petrol engine.

In spite of its heaviness, the Essex V6 was used as the main workhorse and a high performance option for medium to full-sized cars like the Capri the Granada and Transit.

[24] The company Janspeed, well known for their high performance exhaust systems, also designed a turbocharging system for the Ford Essex 3.0 L and 1.6 – 2.0 L OHC engines, although these were much simpler than the turbocharging system offered by Broadspeed, Janspeed promised a 25% increase in horsepower, boosting the engine's power output from 138 hp (140 PS; 103 kW) to around 172 hp (174 PS; 128 kW) using a single Roto-Master turbocharger mounted directly on top of the left bank of the engine providing 5 psi (0.34 bar) of boost.

[27] [28] [29] In 1977, Californian company Olson Engineering, Inc. was contracted by TVR to design modifications to the Essex V6 such that it could be emissions-certified for use in the United States.

An owner's handbook supplement for US Federal models indicates that the emissions control system used a catalytic converter, exhaust gas recirculation, and secondary air injection.

Dealers were made aware of this fact, but were each apparently coerced into buying at least two of the non-compliant cars with the threat of withholding spare parts for other TVR models.

During the long period of time during which Martin Lilley attempted to communicate with US customs officials to resolve the situation, the cars were neglected and stored outside, where they deteriorated and were vandalized.

Late in its production life it was fitted with Lucas controlled electronic fuel injection designed by SAMCOR (South African Motor Corporation – now Ford SA) in co-operation with the University of Pretoria's engineering department.