It was Doug Chivas, I think, Dave in 1972 in an E49. They came in to change the tyres and wheels and for some reason, tried to put new (cold) wheelnuts on studs that were pretty hot. As a result they jammed and they lost time getting it sorted. Brock won in the LJ Torana and John French was second in his (in)famous Wild Violet GTHO (which was the fastest old style car ever down Conrod, faster even than the factory Falcons).
1972 was the year of the rain, so it really was the year that the sixes could have gunned down the eights (and they did with Brock winning). After that, until the Jags in 85 it was a V8 show. In fact, from 75 it was Formula Torana

Apart from 1977.
Chivas drove with Brock in 1973, but, if you remember, they ran out of fuel and he had to push the Torana up the pit road unassisted. Brock is quite brutal when the car gets within the zone where the mechanics can help, and he elbows an exhausted Chivas out of the way.
Even the factory teams were pretty amateurish in those days. True, Ford brought in Turner (an American) and Marsden (a Brit) to run their teams, and Holden had the wily Harry Firth, but mostly it was an amateur show.
I think that is what makes it really interesting for me. Ford versus Holden versus Chrysler; Moffat (the 'foreign' professional baddie) versus Brock (the local boy made good/God); V8 versus six; 'factory' (yes, I know they were dealer teams

) versus the little guys (who occasionally bit back); colour, drama, simpler times.
When Group C became Group A in 1985, it all changed, and the V8Supercars are a yawn now.