The following sites may help -

for victoria -
http://www.ozracing.net.au/vro/handicap/policy.htm

& nsw -
http://www.racingnsw.com.au/page.asp?parm=han.main

I found the following nsw scales some time ago & have found them useful.

HANDICAPPING


Scales
Relative difference between classes

Group 1 handicap 100
GROUP 2 HANDICAP 98
GROUP 3 HANDICAP 96
LISTED HANDICAP 95
OPEN HANDICAP (METRO) 91
TRANSITIONAL HANDICAP
(SATURDAY METRO)
PROVINCIAL OPEN HANDICAP (MIDWEEK) 87
MARES OPEN HANDICAP (METRO) 86
1SC 1YR (SATURDAY)
PROVINCIAL OPEN HANDICAP (SATURDAY) 85
PROVINCIAL TRANSITIONAL (MIDWEEK)
ACT OPEN HANDICAP 83
GOULBURN, M'BROOK, SCONE OPEN HANDICAP 81.5
3YO OPEN HANDICAP (METRO)
PROVINCIAL TRANSITIONAL HANDICAP (SATURDAY)
1SC 1YR (MIDWEEK) 81
0SC 1YR (MIDWEEK)
0SC (MIDWEEK)
COUNTRY OPEN HANDICAP 80
PROVINCIAL CLASS 4 (MIDWEEK) 79
3YO 0SC 78
PROVINCIAL CLASS 4 (SATURDAY) 77
PROVINCIAL CLASS 1-2 (MIDWEEK)
COUNTRY CLASS 4 76
PROVINCIAL CLASS 1-2 (SATURDAY) 75



2yo races handicapped above and below unraced.

Races of 1800m and further in all classes do not contain the overall strength of races run at shorter distances. As such, they are normally scaled approximately 2kg inferior.

These scales are estimated on all races at their strongest level. At various times of the year any or all of these races may be scaled at an inferior level but the relative differences should remain the same.