Hi there Tea,
I think that it really depends on where you are ranked and/or the strength of your cohort.
If you are ranked #1, due to SAC moderation, a 60% and 95% average are inherently the same, as far as VCAA is concerned (it may affect your respective school's awards though).
Additionally, if you are ranked slightly lower (e.g. #2-#10), but go to a competitive school (i.e. Scotch, SEHS, etc.), then it shouldn't make too much of a difference.
However, if you are ranked quite low, at a poorly performing school (due to easy SACs), it may be quite difficult, even if you do ace the exam.
In any case, just try your best, and thus can't be too disappointed in the outcome.
