had applied to the 1972 race, were replaced by the new Group C Touring Car regulations for 1973. Upgrades were allowed to seats, lubrication systems, camshafts, carburettors, suspensions, brakes and wheel rim sizes. These changes advantaged the better resourced teams as a great deal of testing was now needed to optimize the performance of the race cars. Factory teams had the best access to improved components that were often not readily available to private competitors. In 1973 Holden campaigned upgraded XU-1s. Privateers entered improved Chargers. Ford unleashed its new XA model "hard top" coupe Ford Falcon GT which had been pioneered by John Goss. While not designated as a GT-HO, race prepared Hardtop GTs incorporated most of the still born Phase Four's componentry including the four-bolt 351 V8 engine. The 1973 Hardie-Ferodo 1000 started at 9:30 am. When the flag dropped the "no substitute for cubic inches" ethic prevailed as the Goss Falcon hardtop powered away from pole position. At the end of lap one Fords held the first four places with Toranas fifth, six and seventh. The highest placed Charger was in eighth position. Brock inherited the lead when the Fords started pitting for fuel. Brock and co-driver Chivas had contrived a good lead when a miscalculation caused the Torana to run out of fuel at the top of the Mountain. Intending to perform one less pit stop than the Ford teams, HDT team manager Harry Firth had instructed Chivas to "Get Max Laps" via a hand held sign. The XU-1 coasted down Conrod Straight and came to a halt just before the entrance to the Pits. Chivas pushed the XU-1 up hill along pit lane. His pit crew could not lend assistance as this would have resulted in disqualification. By the time the XU-1 was refueled, Moffat was well in front. Brock set off in heroic pursuit of Moffat's Falcon GT but the XU-1 suffered a deflating tyre. Moffat claimed another Falcon victory, his third in only four years. Co-driven by Ian (Pete) Geoghegan the winning Ford was the only Falcon classified as a finisher. 1973 was the last competitive appearance for Chrysler, with the marque disappearing from the Group C category almost entirely. Class wins were achieved by a Datsun 1200, an Alfa GTV, a Mazda RX2 and, of course, the Falcon GT. At the end of the year Ford Australia gave the Falcon GT race cars