These are just a few I have found, I hope you find them interesting:
Reference:
http://southerncrossanniversaryrally.com.au/1968-the-overview/
9 - 13 OCTOBER
SYDNEY – MELBOURNE - SYDNEY
Final Outright Placings
1 John Keran Peter Meyer Volvo 142 S 48 pts
2 Frank Kilfoyle Doug Rutherford Ford Cortina GT 82
3 Colin Bond Brian Hope Mitsubishi Colt 85
4 Tony Roberts Mike Osborne Holden HK 89
5 Bruce Hodgson Bob Forsyth Ford Cortina GT 93
6 Bob Watson Jim McAuliffe Holden HK 108
7 Greg Garard Roy Denny Holden Monaro 117
8 John Garard Barry Waldron Holden Monaro 126
9 Doug Stewart Brian Field Mitsubishi Colt 128
10 Peter Houghton Mick Neilsen Peugeot 404 143Volvos
142S with a Repco head for John Keran/Peter Meyer and Max Winkless/Nigel Collier
144S for Keith Dobbs/Gary Mecak
122S for Lynne Keeffe/Carol Waldron
Also Google:
The 1968 London to Sydney Marathon by Robert Connor, Pages 174 & 178.
States Volvo Sweden's involvement with the Repco cylinder head and which cars had them fitted.This following information is from Wheels Magazine October 1969; pages 39.40,41 &81.