LH
March 1974 had the first completely new Torana body, with the arrival of the larger mid-sized LH series, produced in four-door sedan style only. It resembled other GM products of its generation, notably the Opel Rekord D and particularly in overall size and profile, the closely related FE series Vauxhall Victor. It was unique in that, following the addition of a four-cylinder option in May 1974, the same body style was available with a choice of inline-four, inline-six, or V8 engines, specifically, 1.9-litre Opel four, 2.85- and 3.3-litre Holden 'red' sixes, and 4.2- and 5.0-litre Holden V8s. Low-compression versions of the fours and sixes were also available for export markets.[10]
Exports were made to the Philippines, where it was sold as the "Holden 1900".[11]
The 5.0-litre engine was reserved for the sporting LH Torana SL/R 5000 sedan. A special build derivative of the SL/R 5000 was the Bathurst-intended 'L34 Option', of which only 263 were built, with a higher-compression engine with stouter components for more power and durability in competition use. The most notable external feature of the L34 was the bolt-on wheel arch extensions, designed to accommodate the larger racing rims and tyres.[12]
According to Holden, the top speed of the SL/R 5000 was 208 km/h
The L34 option, which was first seen in 1975, proved to be fast and successful, yet fragile, in Australian touring car racing. It was eventually superseded by the evolutionary A9X option made available in the LX Torana series in 1977. The A9X road car was delivered with a standard L31 5.0 V8 (detuned to comply with emissions laws), but used the L34 motor in races which was developed by Repco for the LH SL/R 5000 H.O. L34. The A9X version of the Torana had a larger 10-bolt Salisbury differential with disc brakes and had the option of the Borg Warner Super T10 four-speed. Hardly any cars were delivered with Super T10 option, so in effect the immortalized A9X was a pretty stock car with a better differential and suspension. The LH Torana in L34 form won the Bathurst 1000 touring car race with Peter Brock and Brian Sampson in 1975 and with Bob Morris and John Fitzpatrick in 1976, with the L34 motor being fitted to the A9X, so in effect winning with that car, as well.
Retailing at some AU$2194 more than the standard LH SL/R 5000, the L34 option was never actually advertised for public sale and all applications to buy one had to be referred to a GM-H zone manager who would then decide if the applicant was a suitable buyer. This quickly led to a rumour that Holden had secretly done a deal with the Confederation of Australian Motorsport (CAMS) and the Australian Government to not sell any of the available race-like L34's to anyone who did not have a then current CAMS competition licence. To test whether this was true or not, Wheels magazine sent one of their journalists to four different Holden dealers across Sydney. Despite receiving various answers as to the availability of an L34 Torana, what was found was that the rumour had indeed been true. Holden dealers across Australia were not permitted to sell an L34 to anyone who did not have a current CAMS racing licence.[13]
According to Holden Dealer Team boss Harry Firth, Holden chose to have the V8 engine in the SL/R 5000 developed by Repco on their dyno which led to massive oil surge problems on the race track and had a number of teams, including the HDT, suffer numerous engine failures in both testing and races in 1974. Firth believed that using the same V8 engine he had developed for the stillborn V8 GTR XU-1 would have solved this problem, as the HDT had already cured the oil problems, but Holden ignored his warnings.
Prototype wagon and hatchback versions of the LH Torana were built, but never reached production. Overall, a total of 70,184 LH Toranas were built. A few special models of the LH were built, the somewhat sporting Plus 4 and G-Pak models. The Plus 4 arrived in September 1974 and was an attempt to move a few more of the slow-selling four-cylinder models.[14] The G-Pak, first seen in February 1975, received the 3.3-litre inline-six. Both came with a four-speed manual, sporting instrumentation, and disc brakes in front.[14]
New Zealand assembly got off to a troubled start. General Motors New Zealand, which still had a wide four-cylinder Vauxhall Viva/Magnum line on sale, had planned a 2850 six 'S' model with bench front seat and three-speed column manual shift and the 3300SL with bucket seats and four-speed manual or three-speed Trimatic floor shift. The New Zealand government, though, imposed a 60% sales tax (a post-first oil crisis measure) on cars with engines over 2.7 litres just as GM launched the LH in mid-'74, and only a few of each were built. The LH was then withdrawn temporarily and relaunched some months later with the Opel 1.9-litre I4 and floor-shift manual or automatic (SL only) gearboxes. Six-cylinder Toranas would never again be built in New Zealand and were only very rare imports after this. GM New Zealand also built a local version of the Australian Plus 4 'sports' special edition, but the changes were only cosmetic - bright paint colours, special wheel trims, black stripes and all-black interior trim.
A9X option
During 1977, the LX series also had the development of another limited-build high-performance option aimed at winning in Australian Touring Car racing, and in particular at the annual Bathurst 1000 touring car race. This 'A9X Option' was available on the 5.0-litre V8-powered SLR 5000 sedan and SS hatchback models.[19] The A9X visually resembled the L34-optioned LH model, but with the addition of a rear-facing bonnet scoop designed to increase airflow into the engine bay (carburettor) to produce maximum power in motor racing applications. The A9X package varied from the old L34 in road form in that whilst the engine was not modified, the A9X nevertheless had some special mechanical features such as rear disc brakes, heavy-duty axles, and a heavy-duty '10 bolt' differential.
After being rushed into Group C touring car racing, Peter Brock gave the A9X a dream debut by winning the 1977 Hang Ten 400 at Sandown. However, after he put his Torana on pole position, the A9X ultimately lost its debut Bathurst race in 1977 to the Ford Falcons of Allan Moffat and Colin Bond. The A9X package was soon refined and proved dominant during the following two seasons of touring-car racing in Australia. Drivers Peter Brock and Bob Morris were victorious in the 1978 and 1979 Australian Touring Car Championships, respectively, and A9Xs shared by Peter Brock and Jim Richards won the 1978 and 1979 Bathurst 1000s. In a show of the A9X's superiority, Brock and Richards won the 1979 race by a record six laps, with Brock setting the touring-car lap record on the last lap of the race.
UC
The introduction of the UC Torana in March 1978 brought the end of V8 power and of the sporting SL/R variant in the Torana range of cars. The UC series featured a significantly altered frontal appearance (The UCs had square headlamps and a smoother front end), and a completely new interior dash layout. Torana was now rationalised to a choice of two equipment levels and two six-cylinder engines, the 2.85-litre and the 3.3-litre. A 'Deluxe Pack' was an option that allowed the UC Torana SL to compete with Ford's TE Cortina Ghia, which comprised laminated windscreen, tinted side and rear windows, intermittent wipers, radio/cassette player, cloth trim, sports instrumentation, and bumper overriders. While the V8 was discontinued in the UC, a factory-sanctioned dealer option of a turbo was offered. This was called the UC SL/T. These were mainly ordered through Suttons in NSW, but one is known to have been ordered through Zupps in Queensland. These were produced in small production runs of five cars and only 33 were built. Only one is known to exist today; it was ordered through Zupps.
The Holden Sunbird was also updated to UC specifications and continued to sell well as a 1.9-litre four-cylinder car, sharing its body architecture with the UC Torana sedan and hatchback. The UC Sunbird expanded into three trim levels: base (manual only), SL, and SL/E. It did very well in New Zealand, where it was assembled, particularly in fleets, where it competed with the Ford Cortina and a variety of Japanese D-segment models.
Early UC Sunbirds retained the 1.9-litre Opel engine used in the LX.[21] Later UC models (from September 1978[22]) had the locally produced 1,892-cc Starfire Four engine that was also installed into the Australian-produced versions of the