Malcolm Fraser would win the snap election, but he would lose a few seats to the Labor Party. In fact, I'm not sure if you knew about this, but Malcolm Fraser was aware of Bill Hayden's ructioning of the Labor Party and would've called a snap election, if he hadn't suffered a back injury.
If you get rid of the back injury, then Malcolm Fraser would of definitely called the snap election to get another term.
Now, if he can patch the 1980s recession and try to avoid leadership challenges, is more difficult to determine.
I do not know much about Australian politics other than the two main parties.