It was obvious that a special 'Bathurst' version of the SLR was needed. In Holden's archives there are photos of the car that might have been: the XU-2, But GMH had had enough bad press with the proposed V8 XU-1, so it chose not to use the XU-2 name. Instead it opted for 'L34', an alpha-numeric combination which-although not displayed anywhere on the exterior of the car - became almost as famous.
Most manufacturers would make a hell of a song and dance if they produced a car half as potent as the 1974 Bathurst Torana. But not GMH. It’s officials all but pretended the newcomer didn't exist. According to Wheels magazine (which eventually got to test an L34):
... an edict was issued by the GMH management that no motoring writer would get an L34 from the company and that the Press was to be discouraged from searching for one elsewhere.
'L34' - a name dredged from Holden's option code-book - referred to the extensive modification option available on the SL/R 5000. The most significant change was a completely new engine block, cast by Repco using its Formula 5000 racing technology. The L34 also had a string of other changes such as fully grooved main bearings, solid skirt pistons, heavy duty conrods, larger main cap bolts, ported and polished head with l .95 inch inlet valves and 1.61 inch exhaust valves. There were special rocker arms with needle bearings, heavy-duty push rods and guide plates, twin point distributor, twin coils, machined intake manifold, special carburettor adaptor plate, extractors, larger sump with anti surge baffles, larger fuel pump and line, improved radiator, lighter flywheel, stronger clutch and a manual choke.
To take the extra pounding, a heavy-duty tail shaft and rear axle tube baffles were added. Improved handling was taken care of by a wider track, heavy-duty suspension and 14 x 6 inch sports wheels. Braking was upgraded by 10.9 inch (276 mm) HQ front discs and 10 inch rear drums. Distinctive bolt-on wheel guard flares covered the wider wheels. The new car appeared without any special badges or decals to alert you, to exactly what was under the skin but there was no doubt that it was a mean package.
Holden claimed the modifications were merely for durability. GMH even claimed the same power figures for the L34 engine as for the standard engine. Who were they kidding? The L34 was priced at $6200 - a piddling amount today but no small ask then, especially since you really had to spend another $1500 on the 'high output pack' if you wanted a full-on race homologation version. This pack included roller rockers, solid lifters, modified exhaust system, racing piston rings and an oil cooler.
A new Holley four-barrel (780cfm) replaced the four-barrel Rochester and the so-called 'Bathurst cam' was fitted. Also available was the superior TI0 four-speed gearbox.
If you could pull together the money, you still had to find the car. They were thin on the ground, and for obvious reasons Holden's sales managers gave preference to those who intended to go racing.
But in spite of the poke and polish of the full house L34, Bathurst 1974 was not a Great Race as far as Holden was concerned. The L34 was four seconds a lap quicker than the Falcons during qualifying but didn't end up at the pointy end of the field on race day. The Goss/ Bartlett Falcon Hardtop won, the L34 was left to fill second, third and fourth places.
By 1975, however, the bugs had been ironed out and Peter Brock took his second Bathurst victory in a race dominated by the super hot Torana L34. In 1976 the L34 again won Bathurst and in the meantime many other races and championships had fallen to the mighty Torana.