If things are smooth, this is an easy connection. I managed CBR-BNE-LAX-JFK straightforwardly a week ago. CBR-BNE was a 90-minute connection (close to or at MCT); it took only 30 minutes from arrival at the domestic gate to be through immigration at the international terminal. BNE-LAX arrives at the TBIT (it departs LAX-BNE from T4), but I had my bag and was out at baggage drop-off within 15 minutes from flight arrival (and I was in row 73 in the back of Y).

However, if you have a sensible option to fly via SYD on the A380, even at the cost of taking AA rather than QF for LAX-JFK, I'd at least consider taking that instead. The 744s are long in the tooth these days.