What is a Series III Stage 1?
The Land Rover Stage 1 1979 to 1985
The Land Rover Stage 1 was so called because it was the first product of an investment programme that lead to the 90 and the 110 (later Defender D90 and D110). It was in effect what many Land Rover owners had been converting their standard SIII's into for many years - a SIII with a larger engine, in fact with the 3.5L V8 out of the Range Rover. The standard SIII gearbox could not really take this kind of power and torque, as the owners of home conversions often found out, so Land Rover fitted the Range Rover's LT95 full-time-4WD transmission too.
The investment programme also produced the 5 door Range Rover, and culminated in the replacement of the Series III Land Rovers by the coil-sprung 110" and 90" Land Rovers in 1983 and 1984 respectively.
The Stage 1 introduced some new features which would be carried forward to the 90/110 range. Permanent four wheel drive - most previous series models had selectable 2 or 4 wheel drive. The radiator was moved forwards which gave us the flat fronted appearance still seen on the Defender. The bonnet was llonger than the 'standard' Series IIIs, rounded at the front and wrapping around at the leading edge. The door locks are mounted in the door skin rather than in the handle aperture (also carried on to military Defenders).
The V8's power was reduced to 90bhp because the SIII handling and brakes were not up to the engine's potential level of performance.This reduction was achieved mainly by fitting restrictor plates in the carburettor intakes. The result was only little more power than the old 2.6L 6-cylinder but still enough torque to pull 3.54:1 differentials.
The restrictors are quite easily removed, allowing the engine performance to increase to standard Range Rover levels : 135 - 140 bhp. This is not however the limit of this engine, as the Rover SD1 versions were rated around 155 bhp as standard, and Land Rover itself constantly uprated the capacity and horsepower of the engine as it was also used in other models.