Realistically how late can I land at Sydney domestic to make it to my international flight??

Hello to my frequent fliers.

I think I have put myself in a bit of a tricky situation but I have exam commitments in Brisbane that cause me to get a 2.25PM qantas flight at the earliest. This would land at 4pm. I have an international qantas flight that departs at 5.50PM🥲🥲🥲. But I’m not checking any bags in and I can check in online.

Is this way too tight????

Thanks!!